Pain management in patients with inflammatory bowel disease: insights for the clinician

Anti-inflammatory and anti-hyperalgesic effects induced by an aqueous aged black garlic extract in rodent models of ulcerative colitis and colitis-associated visceral pain

Inflammatory bowel disease (IBD) is a morbid condition characterized by relapsing-remitting inflammation of the colon, accompanied by persistent gut dysmotility and abdominal pain. Different reports demonstrated biological activities of aged black garlic (ABG), including anti-inflammatory and antioxidant effects. We aimed to investigate beneficial effects exerted by ABGE on colon inflammation by using ex vivo and in vivo experimental models. We investigated the anti-inflammatory effects of an ABG water extract (ABGE) on rat colon specimens exposed to E. coli lipopolysaccharide (LPS), a known ex vivo experimental model of ulcerative colitis. We determined gene expression of various biomarkers involved in inflammation, including interleukin (IL)-1β, IL-6, nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α. Moreover, we studied the acute effects of ABGE on visceral pain associated with colitis induced by 2,4-di-nitrobenzene sulfonic acid (DNBS) injection in rats. ABGE suppressed LPS-induced gene expression of IL-1β, IL-6, NF-kB, and TNF-α. In addition, the acute administration of ABGE (0.03-1 g kg-1) dose-dependently relieved post-inflammatory visceral pain, with the higher dose (1 g kg-1) able to significantly reduce both the behavioral nociceptive response and the entity of abdominal contraction (assessed by electromyography) in response to colorectal distension after the acute administration in DNBS-treated rats. Present findings showed that ABGE could represent a potential strategy for treatment of colitis-associated inflammatory process and visceral pain. The beneficial effects induced by the extract could be related to the pattern of polyphenolic composition, with particular regard to gallic acid and catechin.

Moxibustion ameliorates chronic inflammatory visceral pain via spinal circRNA-miRNA-mRNA networks: a central mechanism study

This study aimed to unveil the central mechanism of moxibustion treating chronic inflammatory visceral pain (CIVP) from the angle of circRNA-miRNA-mRNA networks in the spinal cord. The rat CIVP model was established using a mixture of 5% (w/v) 2,4,6-trinitrobenzene sulfonic acid and 50% ethanol at a volume ratio of 2:1 via enema. Rats in the moxibustion group received herb-partitioned moxibustion at Tianshu (ST25, bilateral) and Qihai (CV6) points. The abdominal withdrawal reflex (AWR), mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL) were adopted for pain behavior observation and pain sensitivity assessment. The circRNA, miRNA, and mRNA expression profiles were detected using the high-throughput sequencing technique. Relevant databases and bioinformatics analysis methods were used to screen for differentially expressed (DE) RNAs and build a circRNA-miRNA-mRNA (competing endogenous RNA) ceRNA regulatory network. The real-time quantitative PCR was employed to verify the sequencing result. CIVP rat models had a significantly higher AWR and lower TWL and MWT than normal rats. Between normal and model rats, there were 103 DE-circRNAs, 16 DE-miRNAs, and 397 DE-mRNAs in the spinal cord. Compared with the model group, the moxibustion group had a lower AWR and higher TWL and MWT; between these two groups, there were 118 DE-circRNAs, 15 DE-miRNAs, and 804 DE-mRNAs in the spinal cord. Two ceRNA networks were chosen to be verified. As a result, moxibustion's analgesic effect on visceral pain in CIVP rats may be associated with regulating the circRNA_02767/rno-miR-483-3p/Gfap network in the spinal cord and improving central sensitization.

Chronic abdominal pain in inflammatory bowel disease: a practical guide

Pain is common in inflammatory bowel disease (IBD), yet many patients feel their pain is not addressed by healthcare professionals. Listening to a patient's concerns about pain, assessing symptoms and acknowledging the impact these have on daily life remain crucial steps in addressing pain in IBD. While acute pain may be effectively controlled by pain medication, chronic pain is more complex and often pharmacological therapies, particularly opioids, are ineffective. Low-dose tricyclic antidepressants and psychological approaches, including cognitive-behavioural therapy, have shown some promise in offering effective pain management while lifestyle changes such as a trial of low-fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet in those with overlapping irritable bowel syndrome may also reduce pain. Patients benefit from a long-term, trusting relationship with their healthcare professional to allow a holistic approach combining pharmacological, psychological, lifestyle and dietary approaches to chronic pain. We present a practical review to facilitate management of chronic abdominal pain in IBD.

IBD-related mental health disorders: where do we go from here?

Inflammatory bowel disease is a complex and debilitating disease which is known to cause mental burden for patients. Even though few studies look at mental health disease in this cohort of patients, there is growing evidence of a correlation between disease activity and prevalence of mental health conditions such as anxiety, depression and post-traumatic stress disorder. In this literature review, the relationship between inflammatory bowel disease and mental health disorders is explored, with an emphasis on recognition, screening and therapeutic options and special considerations for these complex comorbidities. The relationship between medical and psychological disease is not often considered and less well understood and there is a need for further research in these fields. Patients would have much to gain both medically and psychologically from a multidisciplinary approach to this chronic disease association.

New Insights into the Mechanism of Ulva pertusa on Colitis in Mice: Modulation of the Pain and Immune System

Inflammatory bowel diseases (IBDs) involving Crohn's disease (CD) and ulcerative colitis (UC) are gastrointestinal (GI) disorders in which abdominal pain, discomfort, and diarrhea are the major symptoms. The immune system plays an important role in the pathogenesis of IBD and, as indicated by several clinical studies, both innate and adaptative immune response has the faculty to induce gut inflammation in UC patients. An inappropriate mucosal immune response to normal intestinal constituents is a main feature of UC, thus leading to an imbalance in local pro- and anti-inflammatory species. Ulva pertusa, a marine green alga, is known for its important biological properties, which could represent a source of beneficial effects in various human pathologies. We have already demonstrated the anti-inflammatory, antioxidant, and antiapoptotic effects of an Ulva pertusa extract in a murine model of colitis. In this study, we aimed to examine thoroughly Ulva pertusa immunomodulatory and pain-relieving properties. Colitis was induced by using the DNBS model (4 mg in 100 μL of 50% ethanol), whereas Ulva pertusa was administered daily at the dosage of 50 and 100 mg/kg by oral gavage. Ulva pertusa treatments have been shown to relieve abdominal pain while modulating innate and adaptative immune-inflammatory responses. This powerful immunomodulatory activity was specifically linked with TLR4 and NLRP3 inflammasome modulation. In conclusion, our data suggest Ulva pertusa as a valid approach to counteract immune dysregulation and abdominal discomfort in IBD.

Management of Pelvic Pain in Patients with Crohn's Disease-Current Overview

Crohn's disease (CD) is a subtype of chronic inflammatory bowel diseases (IBD) with characteristic skip lesions and transmural inflammation that may affect the entire gastrointestinal tract from the mouth to the anus. Persistent pain is one of the main symptoms of CD. This pain has multifactorial pathogenesis, but most often arises from intestinal inflammation itself, as well as from gut distention or partial intestinal obstruction. Some current evidence also suggests sensitization of sensory pathways, as well as modulation of those signals by the central nervous system, which highlights the impact of biopsychosocial factors. To date, most studies have focused only on the pain located in the abdomen, while pelvic pain has rarely been explored, despite it being a common symptom. The aim of this study is to provide an abbreviated summary of the current state of knowledge on the origins and treatment of pelvic pain in CD.

Medication use among patients with Crohn’s disease or ulcerative colitis before and after the initiation of advanced therapy

Background

Although various treatments help reduce abdominal pain, real-world pain medication utilization among patients with Crohn’s disease (CD) or ulcerative colitis (UC) receiving advanced therapies is poorly understood. The aim is to understand the utilization of pain medication 12 months before and after the initiation of advanced therapies among patients with newly diagnosed CD or UC.

Methods

This retrospective, observational cohort study used administrative medical and pharmacy claims data of patients with CD or UC from HealthCore Integrated Research Database (HIRD®). The data from patients with use of pain medication over 12 months follow-up (after the initiation date of advanced therapies) were collected and analyzed. Differences in the use of pain medication 12 months before and after the initiation of advanced therapies were assessed using McNemar's and Wilcoxon signed-rank test.

Results

Prior to initiating advanced therapies, 23.1% of patients with CD (N = 540) received nonsteroidal anti-inflammatory drugs (NSAIDs), 78.1% glucocorticoids, 49.4% opioids, and 29.3% neuromodulators; similarly, 20.9% of patients with UC (N = 373) received NSAIDs, 91.4% glucocorticoids, 40.8% opioids, and 29.5% neuromodulators. After receiving advanced therapies for 12 months, patients reported a reduction in the use of steroids (78.1% vs. 58.9%, P < 0.001 in CD; 91.4% vs. 74.3%, P < 0.001 in UC), opioids (49.4% vs. 41.5%, P = 0.004 in CD; 40.8% vs. 36.5%, P = 0.194 in UC), and NSAIDs (23.1% vs. 15.0%, P < 0.001 in CD; 20.9% vs. 15.8%, P = 0.035 in UC), while the use of neuromodulators significantly increased (29.3% vs. 33.7%, P = 0.007 in CD; 29.5% vs. 35.7%; P = 0.006 in UC).

Conclusions

The use of pain medications such as NSAIDs, glucocorticoids, opioids, and neuromodulators was common among patients with CD or UC. These results highlight that patients with CD or UC continued to receive pain medications even after initiating advanced therapies.

Appraisals of Pain in Pediatric Inflammatory Bowel Disease: A Qualitative Study With Youth, Parents, and Providers

Background

Pain is a predominant symptom of inflammatory bowel disease (IBD), and is influenced by cognitive, emotional, and behavioral factors. The cognitive-affective model of symptom appraisal (CAMSA) has been used to understand how youth view symptoms in chronic conditions. We sought to (1) determine how youth with IBD and their parents appraise pain, and how their perspectives fit within CAMSA, and (2) explore health care providers' understanding and communication about pain.

Methods

Participants included 19 youth ages 10-17 years with chronic IBD pain and their parents, and 5 IBD providers from a gastroenterology clinic. Separate semi-structured qualitative interviews with youth, parents, and providers were conducted. Interview prompts were adapted from CAMSA, previous studies of pediatric pain and symptom monitoring, and a qualitative study in adults with IBD pain. Interviews were analyzed according to principles of reflexive thematic analysis.

Results

Three key components of CAMSA (IBD Threat, Fear/Worry, and Biased Attending) were identified in youth and parent dyads. Some youth showed Biased Attending, including difficulty disengaging, while other youth simply monitored pain. The overarching theme for provider interviews was Gastroenterologists view pain as a secondary (rather than primary) treatment issue.

Conclusions

CAMSA is potentially applicable to pain appraisal in youth with IBD and their parents. When health care providers communicate about pain, they should consider how symptom uncertainty may be influenced by threat, fear/worry, and biased attending. Further studies are needed to develop and test psychosocial interventions to reduce fear and threat of pain in youth with IBD in partnership with families and providers.

The Efficacy of Camelina sativa Defatted Seed Meal against Colitis-Induced Persistent Visceral Hypersensitivity: The Relevance of PPAR α Receptor Activation in Pain Relief

Brassicaceae are natural sources of bioactive compounds able to promote gut health. Belonging to this plant family, Camelina sativa is an ancient oil crop rich in glucosinolates, polyunsaturated fatty acids, and antioxidants that is attracting renewed attention for its nutraceutical potential. This work aimed at investigating the therapeutic effects of a defatted seed meal (DSM) of Camelina sativa on the colon damage and the persistent visceral hypersensitivity associated with colitis in rats. Inflammation was induced by the intrarectal injection of 2,4-dinitrobenzenesulfonic acid (DNBS). The acute administration of Camelina sativa DSM (0.1–1 g kg⁻¹) showed a dose-dependent pain-relieving effect in DNBS-treated rats. The efficacy of the meal was slightly enhanced after bioactivation with myrosinase, which increased isothiocyanate availability, and drastically decreased by pre-treating the animals with the selective peroxisome proliferator-activated receptor alpha (PPAR α) receptor antagonist GW6471. Repeated treatments with Camelina sativa DSM (1 g kg⁻¹) meal counteracted the development, as well as the persistence, of visceral hyperalgesia in DNBS-treated animals by reducing the intestinal inflammatory damage and preventing enteric neuron damage. In conclusion, Camelina sativa meal might be employed as a nutraceutical tool to manage persistent abdominal pain in patients and to promote gut healing.

Abdominal Pain in Inflammatory Bowel Diseases: A Clinical Challenge

Up to 60% of inflammatory bowel disease (IBD) patients experience abdominal pain in their lifetime regardless of disease activity. Pain negatively affects different areas of daily life and particularly impacts the quality of life of IBD patients. This review provides a comprehensive overview of the multifactorial etiology implicated in the chronic abdominal pain of IBD patients including peripheral sensitization by inflammation, coexistent irritable bowel syndrome, visceral hypersensitivity, alteration of the brain–gut axis, and the multiple factors contributing to pain persistence. Despite the optimal management of intestinal inflammation, chronic abdominal pain can persist, and pharmacological and non-pharmacological approaches are necessary. Integrating psychological support in care models in IBD could decrease disease burden and health care costs. Consequently, a multidisciplinary approach similar to that used for other chronic pain conditions should be recommended.

Beneficial Effects of Eruca sativa Defatted Seed Meal on Visceral Pain and Intestinal Damage Resulting from Colitis in Rats

Most therapies used in patients affected by inflammatory bowel diseases are ineffective in preventing the development of chronic visceral hypersensitivity, mainly due to inflammation-induced enteric neuroplasticity. Glucosinolates, secondary metabolites mainly of Brassicaceae with anti-inflammatory and neuroprotective properties, are effective in treating both neuropathic and arthritis pain through H₂S release and Kv7 potassium channel activation. The aim of this work was to investigate the protective and anti-hyperalgesic efficacy of a defatted seed meal from Eruca sativa Mill. (Brassicaceae), rich in glucosinolates, in a rat model of colitis induced by 2,4-dinitrobenzene sulfonic acid (DNBS). The mechanisms of action were also investigated. Visceral pain was assessed by measuring the abdominal response to colorectal distension. Fifteen days after colitis induction, the acute administration of E. sativa defatted seed meal (0.1–1 g kg⁻¹ p.o.) dose-dependently relieved pain. This effect was hampered by co-administering an H₂S scavenger or a selective Kv7 blocker. Administering E. sativa (1 g kg⁻¹) for 14 days, starting after DNBS injection, contributed to counteracting visceral pain persistence in the post-inflammatory phase of colitis by promoting colon healing from the damage and reducing enteric gliosis. E. sativa defatted seed meal might be employed as a nutraceutical tool for supporting abdominal pain relief in patients.

[Functional Gastrointestinal Disorders in Patients with Inflammatory Bowel Disease]

With emerging more effective drugs, the therapeutic goal of inflammatory bowel disease (IBD) has progressed from clinical remission to mucosal healing. Although the inflammation could be controlled more effectively than before, symptoms such as abdominal pain and bowel habit change is still bothersome to some IBD patients. Recently, these "refractory functional gastrointestinal symptoms" in quiescent IBD patients has been paid more attention. The pathophysiology could be multifactorial with genetics, change in gut motility associated with post inflammatory condition, increased permeability, impaired colorectal function, visceral hypersensitivity and gut microbiota. Because both IBD and functional gastrointestinal disease (FGID) could share similar symptoms and some pathophysiology, it is sometimes challenging to distinguish them exactly. However, to reduce the risk of overtreatment or insufficient control of inflammation, exact diagnosis of functional disease or symptoms in quiescent IBD patients is important. Because there is limited randomized controlled trials or prospective study currently, most of the therapeutic approach in IBD patients are empirical or referred to those of functional gastrointestinal disorders. However, approaches based on pathophysiological mechanisms could give appropriate therapies for both IBD and FGIDs.

Interventions for the management of abdominal pain in Crohn's disease and inflammatory bowel disease

BACKGROUND

Crohn's disease is a remitting and relapsing disorder that can affect the whole gastrointestinal tract. Active disease symptoms include abdominal pain, fatigue, weight loss, and diarrhoea. There is no known cure; however, the disease can be managed, and therefore places a huge financial burden on healthcare systems. Abdominal pain is a common and debilitating symptom of Crohn's and other inflammatory bowel diseases (IBDs), and is multifaceted. Abdominal pain in Crohn's disease could be a symptom of disease relapse or related to medication adverse effects, surgical complications and strictures or adhesions secondary to IBD. In the absence of these factors, around 20 to 50% of people with Crohn's in remission still experience pain.

OBJECTIVES

To assess the efficacy and safety of interventions for managing abdominal pain in people with Crohn's disease and IBD (where data on ulcerative colitis and Crohn's disease could not be separated).

SEARCH METHODS

We searched CENTRAL, MEDLINE, three other databases, and clinical trials registries on 29 April 2021. We also searched the references of trials and systematic reviews for any additional trials.

SELECTION CRITERIA

All published, unpublished, and ongoing randomised trials that compared interventions for the management of abdominal pain in the setting of Crohn's disease and IBD, with other active interventions or standard therapy, placebo, or no therapy were included. We excluded studies that did not report on any abdominal pain outcomes.

DATA COLLECTION AND ANALYSIS

Five review authors independently conducted data extraction and 'Risk of bias' assessment of the included studies. We analysed data using Review Manager 5. We expressed dichotomous and continuous outcomes as risk ratios and mean differences with 95% confidence intervals. We assessed the certainty of the evidence using GRADE methodology.

MAIN RESULTS

We included 14 studies (743 randomised participants). Five studies evaluated participants with Crohn's disease; seven studies evaluated participants with IBD where the data on ulcerative colitis and Crohn's disease could not be separated; and two studies provided separate results for Crohn's disease participants. Studies considered a range of disease activity states. Two studies provided intervention success definitions, whilst the remaining studies measured pain as a continuous outcome on a rating scale. All studies except one measured pain intensity, whilst three studies measured pain frequency. Withdrawals due to adverse events were directly or indirectly reported in 10 studies. No conclusions could be drawn about the efficacy of the majority of the interventions on pain intensity, pain frequency, and treatment success, except for the comparison of transcranial direct current stimulation to sham stimulation. The certainty of the evidence was very low in all but one comparison because of imprecision due to sparse data and risk of bias assessed as unclear or high risk. Two studies compared a low FODMAP diet (n=37) to a sham diet (n=45) in IBD patients. The evidence on pain intensity was of very low certainty (MD -12.00, 95% CI -114.55 to 90.55). One study reported pain intensity separately for CD participants in the low FODMAP group [n=14, mean(SD)=24 (82.3)] and the sham group [n=12, mean(SD)=32 (69.3)]. The same study also reported pain frequency for IBD participants in the low FODMAP group [n=27, mean(SD)=36 (26)] and sham group [n=25, mean(SD)=38(25)] and CD participants in the low FODMAP group [n=14, mean(SD)=36 (138.4)] and sham group [n=12, mean(SD)=48 (128.2)]. Treatment success was not reported. One study compared a low FODMAP diet (n=25) to high FODMAP/normal diet (n=25) in IBD patients. The data reported on pain intensity was unclear. Treatment success and pain frequency were not reported. One study compared medicine-separated moxibustion combined with acupuncture (n=51) versus wheat bran-separated moxibustion combined with shallow acupuncture (n=51) in CD patients. The data reported on pain intensity and frequency were unclear. Treatment success was not reported. One study compared mindfulness with CBT (n=33) versus no treatment (n=33) in IBD patients. The evidence is very uncertain about the effect of this treatment on pain intensity and frequency (MD -37.00, 95% CI -87.29 to 13.29). Treatment success was not reported. One study compared soft non-manipulative osteopathic treatment (n=16) with no treatment besides doctor advice (n=14) in CD patients. The evidence is very uncertain about the effect of this treatment on pain intensity (MD 0.01, 95% CI -1.81 to 1.83). Treatment success and pain frequency were not reported. One study compared stress management (n=15) to self-directed stress management(n=15) and to standard treatment (n=15) in CD patients. The evidence is very uncertain about the effect of these treatments on pain intensity (MD -30.50, 95% CI -58.45 to -2.55 and MD -34.30, 95% CI -61.99 to -6.61). Treatment success and pain frequency were not reported. One study compared enteric-release glyceryl trinitrate (n=34) with placebo (n=36) in CD patients. The data reported on pain intensity was unclear. Treatment success and pain frequency were not reported.  One study compared 100 mg olorinab three times per day (n=8) with 25 mg olorinab three times per day (n=6) in CD patients. Pain intensity was measured as a 30% reduction in weekly average abdominal pain intensity score for the 100mg group (n=5) and the 25mg group (n=6). The evidence is very uncertain about the effect of this treatment on pain intensity (RR 0.66, 95% CI 0.38 to 1.15). Treatment success and pain frequency were not reported. One study compared relaxation training (n=28) to a waitlist (n=28) in IBD patients. The evidence is very uncertain about the effect of this treatment on pain intensity (MD -0.72, 95% CI -1.85 to 0.41). Treatment success and pain frequency were not reported. One study compared web-based education (n=30) with a book-based education (n=30) in IBD patients. The evidence is very uncertain about the effect of this treatment on pain intensity (MD -0.13, 95% CI -1.25 to 0.99). Treatment success and pain frequency were not reported. One study compared yoga (n=50) with no treatment (n=50) in IBD patients. The data reported on treatment success were unclear. Pain frequency and intensity were not reported. One study compared transcranial direct current stimulation (n = 10) to sham stimulation (n = 10) in IBD patients. There may be an improvement in pain intensity when transcranial direct current is compared to sham stimulation (MD -1.65, 95% CI -3.29 to -0.01, low-certainty evidence). Treatment success and pain frequency were not reported. One study compared a kefir diet (Lactobacillus bacteria) to no intervention in IBD patients and provided separate data for their CD participants. The evidence is very uncertain about the effect of this treatment on pain intensity in IBD (MD 0.62, 95% CI 0.17 to 1.07) and CD (MD -1.10, 95% CI -1.67 to -0.53). Treatment success and pain frequency were not reported. Reporting of our secondary outcomes was inconsistent. The most adverse events were reported in the enteric-release glyceryl trinitrate and olorinab studies.  In the enteric-release glyceryl trinitrate study, the adverse events were higher in the intervention arm. In the olorinab study, more adverse events were observed in the higher dose arm of the intervention.  In the studies on non-drug interventions, adverse events tended to be very low or zero. However, no clear judgements regarding adverse events can be drawn for any interventions due to the low number of events. Anxiety and depression were measured and reported at the end of intervention in only one study; therefore, no meaningful conclusions can be drawn for this outcome.

AUTHORS' CONCLUSIONS

We found low certainty evidence that transcranial direct current stimulation may improve pain intensity compared to sham stimulation. We could not reach any conclusions on the efficacy of any other interventions on pain intensity, pain frequency, and treatment success. The certainty of the evidence was very low due to the low numbers of studies and participants in each comparison and clinical heterogeneity amongst the studies. While no serious or total adverse events were elicited explicitly with any of the treatments studied, the reported events were very low. The certainty of the evidence for all comparisons was very low, so no conclusions can be drawn.

Post-inflammatory Abdominal Pain in Patients with Inflammatory Bowel Disease During Remission: A Comprehensive Review

Patients with inflammatory bowel disease often experience ongoing pain even after achieving mucosal healing (i.e., post-inflammatory pain). Factors related to the brain-gut axis, such as peripheral and central sensitization, altered sympatho-vagal balance, hypothalamic-pituitary-adrenal axis activation, and psychosocial factors, play a significant role in the development of post-inflammatory pain. A comprehensive study investigating the interaction between multiple predisposing factors, including clinical psycho-physiological phenotypes, molecular mechanisms, and multi-omics data, is still needed to fully understand the complex mechanism of post-inflammatory pain. Furthermore, current treatment options are limited and new treatments consistent with the underlying pathophysiology are needed to improve clinical outcomes.

Carbonic Anhydrase IV Selective Inhibitors Counteract the Development of Colitis-Associated Visceral Pain in Rats

Persistent pain affecting patients with inflammatory bowel diseases (IBDs) is still very difficult to treat. Carbonic anhydrase (CA) represents an intriguing pharmacological target considering the anti-hyperalgesic efficacy displayed by CA inhibitors in both inflammatory and neuropathic pain models. The aim of this work was to evaluate the effect of inhibiting CA IV, particularly when expressed in the gut, on visceral pain associated with colitis induced by 2,4-di-nitrobenzene sulfonic acid (DNBS) in rats. Visceral sensitivity was assessed by measuring animals' abdominal responses to colorectal distension. Repeated treatment with the selective CA IV inhibitors AB-118 and NIK-67 effectively counteracted the development of visceral pain induced by DNBS. In addition to pain relief, AB-118 showed a protective effect against colon damage. By contrast, the anti-hyperalgesic activity of NIK-67 was independent of colon healing, suggesting a direct protective effect of NIK-67 on visceral sensitivity. The enzymatic activity and the expression of CA IV resulted significantly increased after DNBS injection. NIK-67 normalised CA IV activity in DNBS animals, while AB-118 was partially effective. None of these compounds influenced CA IV expression through the colon. Although further investigations are needed to study the underlying mechanisms, CA IV inhibitors are promising candidates in the search for therapies to relieve visceral pain in IBDs.

Interventions for the management of abdominal pain in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammation of the colon characterised by periods of relapse and remission. It starts in the rectum and can extend throughout the colon. UC and Crohn's disease (CD) are the most common inflammatory bowel diseases (IBDs). However, UC tends to be more common than CD. It has no known cure but can be managed with medication and surgery. However, studies have shown that abdominal pain persists in up to one-third of people with UC in remission. Abdominal pain could be a symptom of relapse of the disease due to adverse effects of medication, surgical complications and strictures or adhesions secondary to UC.

OBJECTIVES

To assess the efficacy and safety of interventions for managing abdominal pain in people with ulcerative colitis.

SEARCH METHODS

We searched CENTRAL, MEDLINE and five other databases and clinical trials registries on 28 April 2021. We contacted authors of relevant studies and ongoing or unpublished trials that may be relevant to the review. We also searched references of trials and systematic reviews for any additional trials.

SELECTION CRITERIA

All published, unpublished and ongoing randomised trials that compared interventions for the management of abdominal pain with other active interventions or standard therapy, placebo or no therapy were included. People with both active and inactive disease were included. We excluded studies that did not report on any abdominal pain outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and 'Risk of bias' assessments. We analysed data using Review Manager 5. We expressed dichotomous and continuous outcomes as risk ratios (RRs) and mean differences (MDs), respectively, with 95% confidence intervals. We assessed the certainty of the evidence using the GRADE methodology.

MAIN RESULTS

We included five studies (360 randomised participants). Studies considered mainly participants in an inactive state of the disease.   No conclusions could be drawn about the efficacy of any of the interventions on pain frequency, pain intensity, and treatment success. The certainty of the evidence was very low for all comparisons because of imprecision due to sparse data, and risk of bias. One study compared a low FODMAPs diet (n=13) to a sham diet (n=13). The evidence is very uncertain about the effect of this treatment on pain frequency (MD -4.00, 95% CI -20.61 to 12.61) and intensity (MD -9.00, 95% CI -20.07 to 2.07). Treatment success was not reported. One study compared relaxation training (n=20) to wait-list (n=20). The evidence is very uncertain about the effect of this treatment on pain frequency at end of intervention (MD 2.60, 95% CI 1.14 to 4.06) and 6-month follow-up (MD 3.30, 95% CI 1.64 to 4.96). Similarly, the evidence is very uncertain about the effect of this treatment on pain intensity at end of intervention (MD -1.70, 95% CI -2.92 to -0.48) and 6-month follow-up (MD -2.30, 95% CI -3.70 to -0.90). Treatment success was not reported. One study compared yoga (n=30) to no intervention (n=30). The study defined treatment success as the presence or absence of pain; however, the data they provided was unclear. Pain frequency and intensity were not reported. One study compared a kefir diet (Lactobacillus bacteria, n=15) to no intervention (n=15). The evidence is very uncertain about the effect of this treatment on pain intensity (MD -0.17, 95% CI -0.91 to 0.57). Pain frequency and treatment success were not reported. One study compared a stellate ganglion block treatment (n=90) to sulfasalazine treatment (n=30). The study defined treatment success as "stomachache"; however, the data they provided was unclear. Pain frequency and intensity were not reported. Two studies reported withdrawals due to adverse events. One study reported withdrawals due to adverse events as zero. Two studies did not report this outcome.  We cannot draw any conclusions about the effects of any of the interventions on withdrawals due to adverse events because of the very limited evidence. The reporting of secondary outcomes was inconsistent. Adverse events tended to be very low or zero. However, we can make no clear judgements about adverse events for any of the interventions, due to the low number of events. Anxiety was measured and reported at end of intervention in only one study (yoga versus no intervention), and depression was not measured in any of the studies. We can therefore draw no meaningful conclusions about these outcomes.

AUTHORS' CONCLUSIONS

We found very low-certainty evidence on the efficacy and safety of interventions for the management of abdominal pain in ulcerative colitis. Pervasive issues with very serious imprecision from small samples size and high risk of bias have led to very low-certainty outcomes, precluding conclusions. While few adverse events and no serious adverse events were reported, the certainty of these findings was again very low for all comparisons, so no conclusions can be drawn. There is a need for further research. We have identified eight ongoing studies in this review, so an update will be warranted. It is key that future research addresses the issues leading to reduced certainty of outcomes, specifically sample size and reporting that leads to high risk of bias. It is also important that if researchers are considering pain as a critical outcome, they should report clearly if participants were pain-free at baseline; in that case, data would be best presented as separate subgroups throughout their research.

Acute visceral pain relief mediated by A3AR agonists in rats: involvement of N-type voltage-gated calcium channels

ABSTRACT

Pharmacological tools for chronic visceral pain management are still limited and inadequate. A3 adenosine receptor (A3AR) agonists are effective in different models of persistent pain. Recently, their activity has been related to the block of N-type voltage-gated Ca2+ channels (Cav2.2) in dorsal root ganglia (DRG) neurons. The present work aimed to evaluate the efficacy of A3AR agonists in reducing postinflammatory visceral hypersensitivity in both male and female rats. Colitis was induced by the intracolonic instillation of 2,4-dinitrobenzenesulfonic acid (DNBS; 30 mg in 0.25 mL 50% EtOH). Visceral hypersensitivity was assessed by measuring the visceromotor response and the abdominal withdrawal reflex to colorectal distension. The effects of A3AR agonists (MRS5980 and Cl-IB-MECA) were evaluated over time after DNBS injection and compared to that of the selective Cav2.2 blocker PD173212, and the clinically used drug linaclotide. A3AR agonists significantly reduced DNBS-evoked visceral pain both in the postinflammatory (14 and 21 days after DNBS injection) and persistence (28 and 35 days after DNBS) phases. Efficacy was comparable to effects induced by linaclotide. PD173212 fully reduced abdominal hypersensitivity to control values, highlighting the role of Cav2.2. The effects of MRS5980 and Cl-IB-MECA were completely abolished by the selective A3AR antagonist MRS1523. Furthermore, patch-clamp recordings showed that A3AR agonists inhibited Cav2.2 in dorsal root ganglia neurons isolated from either control or DNBS-treated rats. The effect on Ca2+ current was PD173212-sensitive and prevented by MRS1523. A3AR agonists are effective in relieving visceral hypersensitivity induced by DNBS, suggesting a potential therapeutic role against abdominal pain.

Opioid Use Among Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Despite reported adverse effects of opioids in patients with inflammatory bowel disease (IBD), the burden of opioid use in this population appears to be high. We performed a systematic review and meta-analysis of prior studies to determine the prevalence of opioid use among patients with IBD as well as risk factors and outcomes associated with opioid use in this population.

METHODS

We conducted a systematic search of MEDLINE, Embase, Web of Science, and the Cochrane Library through November of 2019. Primary outcomes included the prevalence of opioid use and demographic and clinical variables associated with opioid use in patients with IBD. Quality was assessed using the Newcastle-Ottawa scale. We used random-effect meta-analysis to estimate pooled relative risks (RRs) and 95% CIs.

RESULTS

Of 780 citations identified, 31 were included in our study. The prevalence of opioid use was 21% (95% CI, 13%-30%) in the outpatient setting. Likewise, 62% (95% CI, 25%-92%) of patients received opioids while hospitalized for IBD. Opioid use was associated with female sex (RR 1.20; 95% CI 1.03-1.40), depression (1.99; 95% CI 1.80-2.19), substance abuse (4.67; 95% CI 2.87-7.60), prior gastrointestinal surgery (2.33; 95% CI 1.66-3.26), biologic use (1.36; 95% CI 1.06-1.74), and steroid use (1.41; 95% CI 1.04-1.91). Based on the systematic review, opioid use also appeared to be associated with increased IBD activity, healthcare use, infection, and mortality.

CONCLUSION

In a systematic review and meta-analysis, we found that 21% of outpatients with IBD (and 62% of hospitalized patients) are opioid users; use is associated with more severe IBD and increased healthcare use. Further studies are required to determine whether opioids are the cause or an effect of these associations. Nonetheless, urgent interventions are needed to reduce opioid use, improve disease-related outcomes and reduce healthcare costs.

Systematic Review: Psychosocial Correlates of Pain in Pediatric Inflammatory Bowel Disease

BACKGROUND

Pain is a common symptom in pediatric inflammatory bowel disease (IBD) and is associated with poor health outcomes, yet additional knowledge about the psychosocial correlates of pain is needed to optimize clinical care. The purpose of this study is to systematically review the psychosocial factors associated with pain and pain impact in youth diagnosed with IBD within a developmentally informed framework.

METHODS

Manual and electronic searches yielded 2641 references. Two authors conducted screening (98% agreement), and data extraction was performed in duplicate. Average study quality was rated using the National Institutes of Health Quality Assessment Tool.

RESULTS

Ten studies (N = 763 patients; N = 563 Crohn disease, N = 200 ulcerative/ indeterminate colitis) met the inclusion criteria. Findings showed consistent evidence that higher levels of child depression symptoms and child pain catastrophizing were associated with significantly greater pain and pain impact (magnitude of association ranged from small to large across studies). Greater pain and pain impact were also associated with higher levels of child anxiety symptoms, child pain threat, child pain worry, and parent pain catastrophizing. Within the included studies, female sex and disease severity were both significantly associated with pain and pain impact. Study quality was moderate on average.

CONCLUSIONS

There is evidence that child psychosocial factors are associated with pain and pain impact in pediatric IBD; more studies are needed to examine parent- and family-level psychosocial factors. Youth with IBD should be routinely screened for pain severity, pain impact, and psychosocial risk factors such as anxiety/depression.

Current overview of opioids in progression of inflammatory bowel disease; pharmacological and clinical considerations

Inflammatory bowel diseases (IBD) belong to a subgroup of persistent, long-term, progressive, and relapsing inflammatory conditions. IBD may spontaneously develop in the colon, resulting in tumor lesions in inflamed regions of the intestine, such as invasive carcinoma. The benefit of opioids for IBD treatment is still questionable, thereby we investigated databases to provide an overview in this context. This review demonstrates the controversial role of opioids in IBD therapy, their physiological and pharmacological functions in attenuating the IBD symptoms, and in improving inflammatory, oxidative stress, and the quality of life factors in IBD subjects. Data were extracted from clinical, in vitro, and in vivo studies in English, between 1995 and 2019, from PubMed, Google Scholar, Scopus, and Cochrane library. Based on recent reports, there are promising opportunities to target the opioid system and control the IBD symptoms. This study suggests a novel approach for future treatment of functional and inflammatory disorders such as IBD.

Postoperative Pain Management in Patients With Ulcerative Colitis

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders of the gastrointestinal tract including ulcerative colitis (UC) and Crohn's disease. Pain management can be challenging in patients with IBD because there are limitations on the use of analgesics. Use of nonsteroidal anti-inflammatory drugs is not recommended in patients with IBD because there is risk of relapse of IBD and an overall increase in disease activity. Opioids, although frequently used for treating severe acute pain, can have additional risks and complications in patients with IBD such as ileus, toxic megacolon, and narcotic bowel syndrome. Furthermore, little information is available in the literature on pain management in these patients undergoing noncolorectal surgery. This report describes 2 patients with UC in whom postoperative pain following oral and maxillofacial surgery was managed by intravenous patient-controlled analgesia with pentazocine. Apart from the development of acute dystonia in 1 case that was likely due to the use of droperidol for prevention of postoperative nausea and vomiting, postoperative pain was well controlled by pentazocine in both patients without any complications or UC exacerbations.

Safety, Pharmacokinetics, and Efficacy of Olorinab, a Peripherally Acting, Highly Selective, Full Agonist of the Cannabinoid Receptor 2, in a Phase 2a Study of Patients With Chronic Abdominal Pain Associated With Crohn's Disease

Background

This randomized, open-label phase 2a study investigated the safety/tolerability, pharmacokinetics, and efficacy of olorinab-a highly selective, peripherally acting, full agonist of the cannabinoid receptor 2-in patients with Crohn's disease (CD) experiencing abdominal pain.

Methods

Eligible subjects 18-80 years of age with quiescent to mildly active CD were randomized to receive olorinab 25 or 100 mg three times daily for 8 weeks. The primary objective was to assess safety/tolerability.

Results

Fourteen subjects received olorinab 25 mg (N = 6) or 100 mg (N = 8). Ten subjects [4 (67%) in the 25-mg group and 6 (75%) in the 100-mg group] reported a total of 34 treatment-emergent adverse events (TEAEs; 32 grade 1/2, not serious events; 2 grade 3, serious, not treatment-related events). No dose reductions or discontinuations due to TEAEs or deaths were reported. Dose-proportional increases in olorinab exposure from 25 to 100 mg were observed, with minimal accumulation at both doses. At week 8, the mean (SD) change from baseline in average abdominal pain score at peak olorinab plasma concentrations was -4.61 (1.77) in the 25-mg group (P = 0.0043) and -4.57 (2.17) in the 100-mg group (P = 0.0036). The change from baseline at week 8 in the mean (SD) number of pain-free days per week was +1.60 (2.61) in the 25-mg group and +2.33 (3.62) in the 100-mg group. No subject required pain medication on study.

Conclusions

Patients with quiescent to mildly active CD receiving olorinab experienced mild-to-moderate adverse events and an improvement in abdominal pain scores in this study.

Supraspinal Mechanisms of Intestinal Hypersensitivity

Gut inflammation or injury causes intestinal hypersensitivity (IHS) and hyperalgesia, which can persist after the initiating pathology resolves, are often referred to somatic regions and exacerbated by psychological stress, anxiety or depression, suggesting the involvement of both the spinal cord and the brain. The supraspinal mechanisms of IHS remain to be fully elucidated, however, over the last decades the series of intestinal pathology-associated neuroplastic changes in the brain has been revealed, being potentially responsible for the phenomenon. This paper reviews current clinical and experimental data, including the authors' own findings, on these functional, structural, and neurochemical/molecular changes within cortical, subcortical and brainstem regions processing and modulating sensory signals from the gut. As concluded in the review, IHS can develop and maintain due to the bowel inflammation/injury-induced persistent hyperexcitability of viscerosensory brainstem and thalamic nuclei and sensitization of hypothalamic, amygdala, hippocampal, anterior insular, and anterior cingulate cortical areas implicated in the neuroendocrine, emotional and cognitive modulation of visceral sensation and pain. An additional contribution may come from the pathology-triggered dysfunction of the brainstem structures inhibiting nociception. The mechanism underlying IHS-associated regional hyperexcitability is enhanced NMDA-, AMPA- and group I metabotropic receptor-mediated glutamatergic neurotransmission in association with altered neuropeptide Y, corticotropin-releasing factor, and cannabinoid 1 receptor signaling. These alterations are at least partially mediated by brain microglia and local production of cytokines, especially tumor necrosis factor α. Studying the IHS-related brain neuroplasticity in greater depth may enable the development of new therapeutic approaches against chronic abdominal pain in inflammatory bowel disease.

Preoperative Opioid Prescription Is Associated With Major Complications in Patients With Crohn's Disease Undergoing Elective Ileocolic Resection

BACKGROUND

Opioid use has grown exponentially over the last decade. The effect of preoperative opioid prescription in patients with Crohn's disease undergoing surgery is unknown.

OBJECTIVE

The purpose of this study was to identify whether preoperative opioid prescription is associated with adverse postoperative outcomes in Crohn's disease.

DESIGN

This is a single-institution retrospective observational study.

SETTINGS

This study was performed at an academic tertiary care center. Details of preoperative opioid prescription were collected from the Kentucky All-Schedule Prescription Electronic Reporting database and the electronic databases of bordering states.

PATIENTS

Consecutive patients undergoing ileocolic resection for Crohn's disease from 2014 to 2018 were included.

MAIN OUTCOME MEASURES

The outcomes examined were major complications (Clavien-Dindo ≥3a), length of stay, and 30-day hospital readmission.

RESULTS

Fifty one of 118 patients were prescribed opioids within 6 months preoperatively (range, 0-33,760 morphine milligram equivalents). Patients with preoperative opioid prescription compared with no preoperative opioid prescription required more daily opioids during hospital admission (p = 0.024). Nineteen patients had a major postoperative complication (preoperative opioid prescription: 26% (13/51) vs no preoperative opioid prescription: 9% (6/67)). On multivariable analysis, preoperative opioid prescription (OR = 2.994 (95% CI, 1.024-8.751); p = 0.045) was a significant risk factor for a major complication. Preoperative opioid prescription was associated with increased length of stay (p < 0.001) and was a risk factor for readmission (OR = 2.978 (95% CI, 1.075-8.246); p = 0.036). Twenty-four patients were readmitted. Using a cutoff for higher opioid prescription of 300 morphine milligram equivalents within 6 months preoperation (eg, 60 tablets of hydrocodone/acetaminophen 5/325), preoperative opioid prescription remained a risk factor for major postoperative complications (OR = 3.148 (95% CI, 1.110-8.928); p = 0.031).

LIMITATIONS

This was a retrospective study and could not assess nonprescribed opioid use.

CONCLUSIONS

Preoperative opioid prescription was a significant risk factor for adverse outcomes in patients with Crohn's disease undergoing elective ileocolic resection. See Video Abstract at http://links.lww.com/DCR/B113. LA PRESCRIPCIÓN PREOPERATORIA DE OPIOIDES SE ASOCIA CON COMPLICACIONES MAYORES EN PACIENTES CON ENFERMEDAD DE CROHN SOMETIDOS A RESECCIÓN ILEOCÓLICA ELECTIVA: El uso de opioides ha crecido exponencialmente en la última década. Se desconoce el efecto de la prescripción preoperatoria de opioides en pacientes con enfermedad de Crohn sometidos a cirugía.Identificar si la prescripción preoperatoria de opioides está asociada con resultados postoperatorios adversos en la enfermedad de Crohn.Este es un estudio observacional retrospectivo de una sola institución.Este estudio se realizó en un centro académico de atención terciaria. Los detalles de la prescripción preoperatoria de opiáceos se recopilaron de la base de datos de "Kentucky All-Schedule Prescription Electronic Reporting" y de las bases de datos electrónicas de los estados fronterizos.Pacientes consecutivos sometidos a resección ileocólica por enfermedad de Crohn entre 2014-2018.Los resultados examinados fueron complicaciones mayores (Clavien-Dindo ≥3a), duración de la estancia y el reingreso hospitalario de 30 días.A cincuenta y uno de 118 pacientes se le recetaron opioides dentro de los 6 meses preoperatorios (rango, 0 a 33,760 equivalentes de miligramos de morfina). Los pacientes con prescripción preoperatoria de opioides en comparación con ninguna prescripción preoperatoria de opioides requirieron más opioides diarios durante el ingreso hospitalario (p = 0,024). Diecinueve pacientes tuvieron una complicación postoperatoria importante (prescripción preoperatoria de opioides: 26% [13/51] frente a ninguna prescripción preoperatoria de opioides: 9% [6/67]). En el análisis multivariable, la prescripción de opioides preoperatorios (OR = 2.994, IC 95%: 1.024-8.751, p = 0.045) fueron factores de riesgo significativos para una complicación mayor. La prescripción preoperatoria de opioides se asoció con un aumento de la duración de la estadía (p <0.001) y fue un factor de riesgo para el reingreso (OR = 2.978, IC 95%: 1.075-8.246, p = 0.036). Veinticuatro pacientes fueron readmitidos. Utilizando un límite para una mayor prescripción de opioides de 300 miligramos equivalentes de morfina dentro de los 6 meses previos a la operación (p. Ej., 60 tabletas de hidrocodona / acetaminofén 5/325), la prescripción preoperatoria de opioides siguió siendo un factor de riesgo para complicaciones postoperatorias mayores (OR = 3.148 IC 95%: 1.110-8.928, p = 0.031).Este fue un estudio retrospectivo y no pudo evaluar el uso de opioides no prescritos.La prescripción preoperatoria de opioides fue un factor de riesgo significativo para los resultados adversos en pacientes con enfermedad de Crohn sometidos a resección ileocólica electiva. Consulte Video Resumen en http://links.lww.com/DCR/B113.

Deepening the Mechanisms of Visceral Pain Persistence: An Evaluation of the Gut-Spinal Cord Relationship

The management of visceral pain is a major clinical problem in patients affected by gastrointestinal disorders. The poor knowledge about pain chronicization mechanisms prompted us to study the functional and morphological alterations of the gut and nervous system in the animal model of persistent visceral pain caused by 2,4-dinitrobenzenesulfonic acid (DNBS). This agent, injected intrarectally, induced a colonic inflammation peaking on day 3 and remitting progressively from day 7. In concomitance with bowel inflammation, the animals developed visceral hypersensitivity, which persisted after colitis remission for up to three months. On day 14, the administration of pain-relieving drugs (injected intraperitoneally and intrathecally) revealed a mixed nociceptive, inflammatory and neuropathic pain originating from both the peripheral and central nervous system. At this time point, the colonic histological analysis highlighted a partial restitution of the tunica mucosa, transmural collagen deposition, infiltration of mast cells and eosinophils, and upregulation of substance P (SP)-positive nerve fibers, which were surrounded by eosinophils and MHC-II-positive macrophages. A significant activation of microglia and astrocytes was observed in the dorsal and ventral horns of spinal cord. These results suggest that the persistence of visceral pain induced by colitis results from maladaptive plasticity of the enteric, peripheral and central nervous systems.

Injury Characteristics and Outcomes of Patients With Inflammatory Bowel Disease After Trauma: A Propensity Score Matched Analysis

BACKGROUND

The clinical course of patients with inflammatory bowel disease (IBD) after trauma is largely unknown. We sought to compare the clinical course of patients with IBD to those without.

METHODS

We conducted a retrospective case-control study of adult patients admitted to a level-1 trauma center from January 1, 2008, through October 1, 2015. Seventy-five patients with IBD were identified. Cases were matched to controls by age, sex, injury severity, and mechanism using 4:1 propensity score-matching analysis. Injury characteristics, clinical course, and infectious and noninfectious complications were compared using bivariate and multivariate analysis.

RESULTS

Participants had a mean age of 56 years and mean injury severity score of 15. Of the 75 cases, 44% had ulcerative colitis, 44% had Crohn's disease, and 12% had undetermined type. More cases were on an immunosuppressant (19% vs 2%, P < 0.01) or steroids (8% vs 2%, P = 0.02) on admission compared with controls. More cases had prior abdominal surgery (P = 0.01). Cases had fewer brain injuries (P = 0.02) and higher admission Glasgow Coma Scale (P < 0.01) but required more neurosurgical intervention (P = 0.03). Cases required more orthopedic surgeries (P < 0.01) and more pain management consultations (P = 0.04). In multivariable analysis, IBD was associated with increased odds of operative intervention, pain management consultation, venous thromboembolism, and longer hospital stay (P < 0.05). Patients on immunosuppressants had increased odds of requiring surgery (P = 0.04), particularly orthopedic surgery (P < 0.01).

CONCLUSIONS

Baseline factors associated with inflammatory bowel disease may place patients at higher risk for surgery and complications after trauma.

Pomegranate Mesocarp against Colitis-Induced Visceral Pain in Rats: Effects of a Decoction and Its Fractions

The management of chronic visceral pain related to Inflammatory Bowel Diseases or Irritable Bowel Syndrome is still a clinical problem and new therapeutic strategies continue to be investigated. In the present study, the efficacy of a pomegranate decoction and of its polysaccharide and ellagitannin components in preventing the development of colitis-induced abdominal pain in rats was evaluated. After colitis induction by 2,4-dinitrobenzenesulfonic acid (DNBS), the pomegranate decoction (300 mg kg-1), polysaccharides (300 mg kg-1), and ellagitannins (45 mg kg-1) were orally administered for 14 days. Repeated treatment with decoction reduced visceral hypersensitivity in the colitic animals both at 7 and 14 days. Similar efficacy was shown by polysaccharides, but with lower potency. Ellagitannins administered at dose equivalent to decoction content showed higher efficacy in reducing the development of visceral pain. Macroscopic and microscopic evaluations performed on the colon 14 days after the damage showed that all three preparations reduced the overall amount of mast cells, the number of degranulated mast cells, and the density of collagen fibers in the mucosal stroma. Although ellagitannins seem to be responsible for most of the beneficial effects of pomegranate on DNBS-induced colitis, the polysaccharides support and enhance its effect. Therefore, pomegranate mesocarp preparations could represent a complementary approach to conventional therapies for promoting abdominal pain relief.

Antidepressants in inflammatory bowel disease

Gut-brain dysregulation has been recognized by the scientific community as being crucial to the understanding of chronic gastrointestinal conditions, and this has translated into the practice of a newly established discipline, psychogastroenterology. Along with psychotherapy, antidepressants (a subtype of central neuromodulators) have been proposed as treatments for gut-brain disorders that might benefit both psychological and gastrointestinal health. Antidepressants have been found to be effective for the treatment of comorbid anxiety and depression, pain and impaired sleep. Although the efficacy of antidepressants is well established in disorders of gut-brain interaction (DGBI), evidence is only now emerging in IBD. This Perspective discusses the use of antidepressants in DGBI and IBD, focusing on how what we have learnt about the role of antidepressants in DGBI could be applied to help optimize the management of IBD.

Beyond neurotransmission: acetylcholine in immunity and inflammation

Acetylcholine (ACh) is best known as a neurotransmitter and was the first such molecule identified. ACh signalling in the neuronal cholinergic system has long been known to regulate numerous biological processes (reviewed by Beckmann and Lips). In actuality, ACh is a ubiquitous signalling molecule that is produced by numerous non-neuronal cell types and even by some single-celled organisms. Within multicellular organisms, a non-neuronal cholinergic system that includes the immune system functions in parallel with the neuronal cholinergic system. Several immune cell types both respond to ACh signals and can directly produce ACh. Recent work from our laboratory has demonstrated that the capacity to produce ACh is an intrinsic property of T cells responding to viral infection, and that this ability to produce ACh is dependent upon IL-21 signalling to the T cells. Furthermore, during infection this immune-derived ACh is necessary for the T cells to migrate into infected tissues. In this review, we will discuss the various sources of ACh that are relevant during immune responses and describe how ACh acts on immune cells to influence their functions. We will also address the clinical implications of this fascinating aspect of immunity, focusing on ACh's role in the migration of T cells during infection and cancer.

Biopsychosocial Correlates of Presence and Intensity of Pain in Adolescents With Inflammatory Bowel Disease

Background: There is growing consensus that pain in pediatric inflammatory bowel disease (IBD) is not fully explained by disease-related processes. However, previous studies have largely measured individual biological, psychological, or social risk factors for pain in isolation. Further, not all youth with IBD presenting to clinic will report presence of pain, and those who do vary in their reports of pain intensity. This study therefore extends prior research by determining biopsychosocial correlates of both presence and intensity of pain in adolescents with IBD, in order to inform targeted pain management intervention approaches. Methods: Adolescents with IBD followed at SickKids, Toronto, and their parents were consecutively enrolled from outpatient clinic. IBD characteristics (diagnosis, time since diagnosis, patient-reported disease activity) were collected. Adolescents reported on current pain (NRS-10), internalizing symptoms (Strengths and Difficulties Questionnaire), and pain catastrophizing (Pain Catastrophizing Scale-Child). Parents reported on protective responses to child pain (Adult Responses to Child Pain) and pain catastrophizing (Pain Catastrophizing Scale-Child). Hurdle models were conducted to examine predictors of presence and intensity of pain in the same model. Biological (patient-reported disease activity, IBD diagnosis subtype, illness duration), psychological (internalizing symptoms, pain catastrophizing), and social (parent pain catastrophizing, parent protective responses) factors were entered as predictors, adjusting for age and sex. Results: Participants included 100 adolescents (12-18; Mean = 15 years) with IBD (60% Crohn's Disease, 40% Ulcerative Colitis or IBD-unclassified) and 76 parents. The majority of the sample was in clinical remission or reported minimal symptoms. Half of participants reported no current pain; for those reporting pain, intensity ranged 1-7 (M = 3.43, SD = 1.98). Disease activity (OR = 53.91, p < 0.001) and adolescent internalizing symptoms (OR = 7.62, p = 0.03) were significant predictors of presence of pain. Disease activity (RR = 1.37, p = 0.03) and parent protective responses (RR = 1.45, p = 0.02) were significant predictors of intensity of pain. Conclusions: Results suggest that the experience of pain in pediatric IBD is biopsychosocially determined. Patient-reported disease activity and internalizing symptoms predicted presence of pain, while disease activity and parent protective responses predicted intensity of pain. While medical intervention in pediatric IBD is focused on disease management, results suggest that depression/anxiety symptoms as well as parent protective responses may be important targets of pain management interventions in pediatric IBD.

Researching New Therapeutic Approaches for Abdominal Visceral Pain Treatment: Preclinical Effects of an Assembled System of Molecules of Vegetal Origin

Abdominal pain is a frequent symptom of irritable bowel syndrome (IBS) and inflammatory bowel diseases (IBDs). Although the knowledge of these pathologies is progressing, new therapeutic strategies continue to be investigated. In the present study, the effect of a system of molecules of natural origin (a medical device according to EU Directive 93/42/EC, engineered starting from Boswellia serrata resins, Aloe vera polysaccharides and Matricaria chamomilla and Melissa officinalis polyphenols) was evaluated against the intestinal damage and visceral pain development in DNBS-induced colitis model in rats. The system (250 and 500 mg kg⁻¹) was orally administered once daily, starting three days before the injection of 2,4-dinitrobenzenesulfonic acid (DNBS) and for 14 days thereafter. The viscero-motor response (VMR) to colon-rectal balloon distension (CRD) was used as measure of visceral sensitivity. The product significantly reduced the VMR of DNBS-treated animals. Its effect on pain threshold was better than dexamethasone and mesalazine, and not lower than amitriptyline and otilonium bromide. At microscopic and macroscopic level, the tested system was more effective in protecting the intestinal mucosa than dexamethasone and mesalazine, promoting the healing of tissue lesions. Therefore, we suggest that the described system of molecules of natural origin may represent a therapeutic option to manage painful bowel diseases.

A Review of the Effects of Pain and Analgesia on Immune System Function and Inflammation: Relevance for Preclinical Studies

One of the most significant challenges facing investigators, laboratory animal veterinarians, and IACUCs, is how to balance appropriate analgesic use, animal welfare, and analgesic impact on experimental results. This is particularly true for in vivo studies on immune system function and inflammatory disease. Often times the effects of analgesic drugs on a particular immune function or model are incomplete or don't exist. Further complicating the picture is evidence of the very tight integration and bidirectional functionality between the immune system and branches of the nervous system involved in nociception and pain. These relationships have advanced the concept of understanding pain as a protective neuroimmune function and recognizing pathologic pain as a neuroimmune disease. This review strives to summarize extant literature on the effects of pain and analgesia on immune system function and inflammation in the context of preclinical in vivo studies. The authors hope this work will help to guide selection of analgesics for preclinical studies of inflammatory disease and immune system function.

Moxibustion Eases Chronic Inflammatory Visceral Pain In Rats Via MAPK Signaling Pathway In The Spinal Cord

Purpose

The purpose of this study was to explore the central analgesia mechanism of moxibustion for chronic inflammatory visceral pain (CIVP).

Methods

A CIVP rat model was established by 2,4,6-trinitrobenzene sulfonic acid (TNBS) plus 50% ethanol via enema. The analgesic effect of moxibustion was evaluated using the abdominal withdrawal reflex (AWR), mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL). The expression profile of phosphorylated proteins of the mitogen-activated protein kinase (MAPK) signaling pathway in the spinal cord was assayed by protein microarray. The differentially expressed proteins were examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for functional clusters and corresponding signaling pathways.

Results

Moxibustion exerted a significant analgesic effect for CIVP rats, mainly presenting as a decrease in the AWR score (all P<0.01) under different levels of distending pressure and an increase in MWT and TWL thresholds (all P<0.05). Compared with the normal group, 76 proteins were upregulated while 15 were downregulated, and MAPK signaling pathway was activated in the model group. Compared with the model group, there were 53 downregulated and 38 upregulated proteins in the moxibustion group, and MAPK signaling pathway was inhibited. Fold change (FC)>1.3 or <0.77 was taken as the screening standard to define the differentially expressed proteins. Fifteen differentially expressed proteins upregulated in the model group were downregulated in the moxibustion group. GO analysis showed that the differentially expressed proteins mainly controlled cellular metabolism regulation, transportation, and stress reactions. KEGG analysis revealed that these differentially expressed proteins were mostly involved in the ERK, JNK, and p38 pathways, and the ERK pathway was predominant.

Conclusion

Moxibustion mitigates CIVP in rats and inhibits the phosphorylation of proteins in the spinal MAPK signaling pathway. The analgesic effect of moxibustion may be associated with the regulation of the spinal MAPK signaling pathway.

Patient views about the impact of ulcerative colitis and its management with drug treatment and surgery: a nested qualitative study within the CONSTRUCT trial

Background

A nested qualitative interview study within the CONSTRUCT trial was conducted to explore experiences and perceptions of patients with acute severe ulcerative colitis following treatment with infliximab or ciclosporin, surgery, or other medication.

Methods

Two hundred seventy patients with steroid-resistant ulcerative colitis were randomised to either infliximab or ciclosporin. Interviews were conducted with 20 trial participants. Thirty-five data capture events took place in total, 20 interviews conducted 3 months after treatment and a further 15 interviews with the same cohort as second interviews at 12 months.

Results

Disease duration varied but similar stories emerged about how people adjusted to living with ulcerative colitis. Issues raised by patients included; the debilitating effect of the disease on quality of life, living with the unpredictability of symptoms and treatment, dealing with embarrassment and stigma and the desire to share knowledge of the disease with others to combat the private nature of this debilitating illness and bring greater visibility to patient experience of symptoms and outcomes.

Conclusion

Patients were more positive about treatment with infliximab than ciclosporin, mainly due to the cumbersome intravenous regimen required for ciclosporin. Prompt diagnosis is required and early reporting of changes in symptoms is encouraged to ensure appropriate treatment.

Trial registration

This trial is registered with the ISRCTN registry; number ISRCTN22663589. The date of registration was 16/05/2008.

Psychological and Social Factors Associated with Pain in Inflammatory Bowel Disease: A Systematic Literature Review of the Evidence in Adult and Pediatric Studies

Background

Pain is commonly experienced in both active and dormant inflammatory bowel disease (IBD). Psychological and social factors, which can be key to pain experience, have been relatively neglected; the only prior comprehensive review focused solely on studies of adults. The present review, therefore, sought to systematically examine relationships between pediatric and adult experience of pain and psychosocial variables.

Method

Systematic searches of 5 databases were conducted to identify studies including measures of pain and psychosocial variables, in pediatric or adult IBD populations. Quality appraisal of studies was undertaken using a qualified assessment tool.

Results

Twenty-three articles met the inclusion criteria. Ten examined relationships between pain and psychosocial variables in adults, and 13 examined in pediatric populations. Inverse relationships were identified between pain and quality of life (QOL) in both populations, with potential differences in pain localization between the two populations. Psychological distress, notably depression, was also important in both populations, with inconsistent evidence for a role for anxiety in pediatric samples. Specific coping styles, and familial responses to communications, also appeared relevant, but with weaker evidence. There was substantial heterogeneity in measures, statistical analyses and sample characteristics, and quality appraisal revealed methodological weaknesses.

Conclusions

Significant relationships were found between pain and various psychological indices, notably QOL and depression. However, most studies were underpowered, did not sufficiently control for key confounds, and almost exclusively reported on Western participants. Adequately powered, statistically sound studies encompassing diverse populations are required to further clarify relationships between pain and psychosocial variables in IBD.

Computational drug repurposing for inflammatory bowel disease using genetic information

As knowledge of the genetics behind inflammatory bowel disease (IBD) has continually improved, there has been a demand for methods that can use this data in a clinically significant way. Genome-wide association analyses for IBD have identified 232 risk genetic loci for the disorder. While identification of these risk loci enriches our understanding of the underlying biology of the disorder, their identification does not serve a clinical purpose. A potential use of this genetic information is to look for potential IBD drugs that target these loci in a procedure known as drug repurposing. The demand for new drug treatments for IBD is high due to the side effects and high costs of current treatments. We hypothesize that IBD genetic variants obtained from GWAS and the candidate genes prioritized from the variants have a causal relationship with IBD drug targets. A computational drug repositioning study was done due to its efficiency and inexpensiveness compared to traditional in vitro or biochemical approaches. Our approach for drug repurposing was multi-layered; it not only focused on the interactions between drugs and risk IBD genes, but also the interactions between drugs and all of the biological pathways the risk genes are involved in. We prioritized IBD candidate genes using identified genetic variants and identified potential drug targets and drugs that can be potentially repositioned or developed for IBD using the identified candidate genes. Our analysis strategy can be applied to repurpose drugs for other complex diseases using their risk genes identified from genetic analysis.

Focus on current and future management possibilities in inflammatory bowel disease-related chronic pain

INTRODUCTION

Visceral pain is a symptom reported by over 70% of inflammatory bowel disease (IBD) sufferers. So far, a single, specific cause of this debilitating state has not been established. Chronic pain is one of the most important factors decreasing the quality of life in IBD course. Concurrently, management of pain is the most challenging issue encountered by clinicians in IBD treatment.

AREAS COVERED

This review focuses on pathophysiology of inflammatory bowel disease-caused visceral pain and explores currently available approaches to its management. We also covered recent pharmacological developments in the field.

CONCLUSIONS

Pain-related disability has major effects on quality of life and on functional and social outcomes in IBD patients. Currently, there is no one standardized method of managing chronic visceral pain in IBD. Therefore, future development, focusing primarily on alleviating the pain, but also on reducing inflammation, is essential.

Incidence and predictors of new persistent opioid use following inflammatory bowel disease flares treated with oral corticosteroids

BACKGROUND

Opioids are commonly prescribed to manage pain associated with inflammatory bowel disease (IBD). It is unknown what percentage of patients develop new persistent opioid use following a steroid-treated IBD flare.

AIM

To identify the incidence and the predictors of new persistent opioid use following an IBD flare.

METHODS

We used a national insurance claim dataset to identify patients with IBD who received an opioid medication around the time of a corticosteroid-treated IBD flare. Patients were stratified as previously opioid naïve, intermittent users, or chronic users. The incidence of persistent opioid use among the opioid-naïve cohort was evaluated along with associated predictors.

RESULTS

We identified 15 119 IBD patients who received opioids around the time of a flare. 5411 (35.8%) were opioid-naïve patients of which 35.0% developed persistent opioid use after the flare. Factors associated with new persistent opioid use include a history of depression (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.13-1.47), substance abuse (HR 1.36, 95% CI 1.2-1.54), chronic obstructive pulmonary disease (COPD) (HR 1.17, 95% CI 1.04-1.3), as well as, Crohn's disease (HR 1.26, 95% CI 1.14-1.4) or indeterminate colitis (HR 1.6, 95% CI 1.36-1.88).

CONCLUSIONS

New persistent opioid use is common in IBD patients who experience a flare, especially among those with mental health disorders, COPD, and Crohn's disease or indeterminate colitis. These findings can be helpful in risk-stratifying patients when choosing an acute pain therapy and providing counselling before choosing to prescribe opioids to opioid-naïve patients experiencing an IBD flare.

Stress Triggers Flare of Inflammatory Bowel Disease in Children and Adults

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease characterized by chronic and relapsing manifestations. It is noteworthy that the prevalence of IBD is gradually increasing in both children and adults. Currently, the pathogenesis of IBD remains to be completely elucidated. IBD is believed to occur through interactions among genetics, environmental factors, and the gut microbiota. However, the relapsing and remitting course of IBD underlines the importance of other modifiers, such as psychological stress. Growing evidence from clinical and experimental studies suggests that stress acts as a promoting or relapsing factor for IBD. Importantly, recent studies have reported an increasing incidence of anxiety or depression in both children and adults with IBD. In this article, we review the mechanisms by which stress affects IBD, such as via impaired intestinal barrier function, disturbance of the gut microbiota, intestinal dysmotility, and immune and neuroendocrine dysfunction. With regard to both children and adults, we provide recent evidence to describe how stress can affect IBD at various stages. Furthermore, we emphasize the importance of mental healing and discuss the value of approaches targeting stress in clinical management to develop enhanced strategies for the prevention and treatment of IBD.

Starting Young: Trends in Opioid Therapy Among US Adolescents and Young Adults With Inflammatory Bowel Disease in the Truven MarketScan Database Between 2007 and 2015

Background

Opioids are commonly prescribed for relief in inflammatory bowel disease (IBD). Emerging evidence suggests that adolescents and young adults are a vulnerable population at particular risk of becoming chronic opioid users and experiencing adverse effects.

Objectives

This study evaluates trends in the prevalence and persistence of chronic opioid therapy in adolescents and young adults with IBD in the United States.

Method

A longitudinal retrospective cohort analysis was conducted with the Truven MarketScan Database from 2007 to 2015. Study subjects were 15-29 years old with ≥2 IBD diagnoses (Crohn's: 555/K50; ulcerative colitis: 556/K51). Opioid therapy was identified with prescription claims within the Truven therapeutic class 60: opioid agonists. Persistence of opioid use was evaluated by survival analysis for patients who remained in the database for at least 3 years following index chronic opioid therapy use.

Results

In a cohort containing 93,668 patients, 18.2% received chronic opioid therapy. The annual prevalence of chronic opioid therapy increased from 9.3% in 2007 to 10.8% in 2015 (P < 0.01), peaking at 12.2% in 2011. Opioid prescriptions per patient per year were stable (approximately 5). Post hoc Poisson regression analyses demonstrated that the number of opioid pills dispensed per year increased with age and was higher among males. Among the 2503 patients receiving chronic opioid therapy and followed longitudinally, 30.5% were maintained on chronic opioid therapy for 2 years, and 5.3% for all 4 years.

Conclusion

Sustained chronic opioid use in adolescents and young adults with IBD is increasingly common, underscoring the need for screening and intervention for this vulnerable population.