Colonic regular contractile frequency patterns in irritable bowel syndrome: the 'spastic colon' revisited

Recent updates on classification and unsolved issues of diverticular disease: a narrative review

Recently, a paradigm shift has occurred in the classification of diverticular disease and the understanding of its pathogenesis. Diverticular disease is now defined as a variety of clinically significant conditions such as diverticulitis, diverticular bleeding, symptomatic uncomplicated diverticular disease, and segmental colitis associated with diverticulosis. Low-grade inflammation, visceral hypersensitivity, abnormal intestinal motility, and genetic factors have emerged as the key contributors to the pathogenesis of diverticular disease. Routine antibiotic use is no longer recommended for all cases of diverticulitis, and simple recurrence is not an indication for surgical treatment. Early colonoscopy with proper preparation is recommended for the treatment of diverticular bleeding, although recent studies have not shown significant efficacy in preventing recurrence. The roles of dietary fiber, nonabsorbable antibiotics, 5-aminosalicylates, and probiotics in the prevention of diverticular disease are controversial and require further investigation.

Not a general, symptom-unspecific, transdiagnostic marker for functional symptoms: sensorimotor processing of head control is intact in chronic pain

Introduction

Functional disorders are prevalent in all medical fields and pose a tremendous public health problem, with pain being one of the most common functional symptoms. Understanding the underlying, potentially unifying mechanism in functional (pain) disorders is instrumental in facilitating timely diagnosis, stigma reduction, and adequate treatment options. Neuroscientific models of perception suggest that functional symptoms arise due to dysregulated sensorimotor processing in the central nervous system, with brain-based predictions dominating the eventual percept. Experimental evidence for this transdiagnostic mechanism has been established in various functional symptoms. The goal of the current study was to investigate whether erroneous sensorimotor processing is an underlying transdiagnostic mechanism in chronic (functional) pain.

Method

A total of 13 patients with chronic (functional) pain [three patients with chronic (functional) pain disorder, F45.40, ICD-10; 10 patients with chronic pain disorder with somatic and psychological factors, F45.41, ICD-10]; and 15 healthy controls performed large combined eye-head gaze shifts toward visual targets, naturally and with increased head moment of inertia. We simultaneously measured participants' eye and head movements to assess head oscillations at the end of the gaze shift, which are an established indicator of (transdiagnostic) sensorimotor processing deficits of head control.

Results

Using a Bayesian analysis protocol, we found that patients with chronic (functional) pain and control participants stabilized their heads equally well (Bayes Factor 01 = 3.7, Bayes Factor exclusion = 5.23; corresponding to substantial evidence) during all sessions of the experiment.

Conclusion

Our results suggest that patients with chronic (functional) pain do not show measurable symptom-unspecific sensorimotor processing deficits. We discuss outcome parameter choice, organ system specificity, and selection of patient diagnoses as possible reasons for this result and recommend future avenues for research.

Updates in the understanding and management of diverticular disease

PURPOSE OF REVIEW

Diverticulosis leads to significant morbidity and mortality and is increasing in prevalence worldwide. In this paper, we review the clinical features, diagnosis, and management of diverticular disorders, followed by a discussion of recent updates and changes in the clinical approach to diverticular disease.

RECENT FINDINGS

Recent literature suggests that antibiotics are likely not necessary for low-risk patients with acute uncomplicated diverticulitis, and not all patients with recurrent diverticulitis require colectomy. Dietary restrictions do not prevent recurrent diverticulitis. Visceral hypersensitivity is increasingly being recognized as a cause of persistent abdominal pain after acute diverticulitis and should be considered along with chronic smoldering diverticulitis, segmental colitis associated with diverticula, and symptomatic uncomplicated diverticular disease.

SUMMARY

Clinicians should be aware that traditionally held assumptions regarding the prevention and management of diverticular disorders have recently been called into question and should adjust their clinical practice accordingly.

Update on the management of sigmoid diverticulitis

Diverticular disease and diverticulitis are the most common non-cancerous pathology of the colon. It has traditionally been considered a disease of the elderly and associated with cultural and dietary habits. There has been a growing evolution in our understanding and the treatment guidelines for this disease. To provide an updated review of the epidemiology, pathogenesis, classification and highlight changes in the medical and surgical management of diverticulitis. Diverticulitis is increasingly being seen in young patients (< 50 years). Genetic contributions to diverticulitis may be larger than previously thought. Potential similarities and overlap with inflammatory bowel disease and irritable bowel syndrome exist. Computed tomography imaging represents the standard to classify the severity of diverticulitis. Modifications to the traditional Hinchey classification might serve to better delineate mild and intermediate forms as well as better classify chronic presentations of diverticulitis. Non-operative management is primarily based on antibiotics and supportive measures, but antibiotics may be omitted in mild cases. Interval colonoscopy remains advisable after an acute attack, particularly after a complicated form. Acute surgery is needed for the most severe as well as refractory cases, whereas elective resections are individualized and should be considered for chronic, smoldering, or recurrent forms and respective complications (stricture, fistula, etc.) and for patients with factors highly predictive of recurrent attacks. Diverticulitis is no longer a disease of the elderly. Our evolving understanding of diverticulitis as a clinical entity has led into a more nuanced approach in both the medical and surgical management of this common disease. Non-surgical management remains the appropriate treatment for greater than 70% of patients. In individuals with non-relenting, persistent, or recurrent symptoms and those with complicated disease and sequelae, a segmental colectomy remains the most effective surgical treatment in the acute, chronic, or elective-prophylactic setting.

Long-term Outcome of Surgery Versus Conservative Management for Recurrent and Ongoing Complaints After an Episode of Diverticulitis: 5-year Follow-up Results of a Multicenter Randomized Controlled Trial (DIRECT-Trial)

OBJECTIVE

The aim of this study was to establish whether surgical or conservative treatment leads to a higher quality of life (QoL) in patients with recurring diverticulitis and/or ongoing complaints.

SUMMARY OF BACKGROUND DATA

The 6 months' results of the DIRECT trial, a randomized trial comparing elective sigmoidectomy with conservative management in patients with recurring diverticulitis (>2 episodes within 2 years) and/or ongoing complaints (>3 months) after an episode of diverticulitis, demonstrated a significantly higher QoL after elective sigmoidectomy. The aim of the present study was to evaluate QoL at 5-year follow-up.

METHODS

From January 2010 to June 2014, 109 patients were randomized to either elective sigmoidectomy (N = 53) or conservative management (N = 56). In the present study, the primary outcome was QoL measured by the Gastrointestinal Quality of Life Index (GIQLI) at 5-year follow-up. Secondary outcome measures were SF-36 score, Visual Analogue Score (VAS) pain score, EuroQol-5D-3L (EQ-5D-3L) score, morbidity, mortality, perioperative complications, and long-term operative outcome.

RESULTS

At 5-year follow-up, mean GIQLI score was significantly higher in the operative group [118.2 (SD 21.0)] than the conservative group [108.5 (SD 20.0)] with a mean difference of 9.7 (95% confidence interval 1.7-17.7). All secondary QoL outcome measures showed significantly better results in the operative group, with a higher SF-36 physical (P = 0.030) and mental score (P = 0.010), higher EQ5D score (P = 0.016), and a lower VAS pain score (P = 0.011). Twenty-six (46%) patients in the conservative group ultimately required surgery due to severe ongoing complaints. Of the operatively treated patients, 8 (11%) patients had anastomotic leakage and reinterventions were required in 11 (15%) patients.

CONCLUSION

Consistent with the short-term results of the DIRECT trial, elective sigmoidectomy resulted in a significantly increased QoL at 5-year follow-up compared with conservative management in patients with recurring diverticulitis and/or ongoing complaints. Surgeons should counsel these patients for elective sigmoidectomy weighing superior QoL, less pain, and lower risk of new recurrences against the complication risk of surgery.

Diagnosis of symptomatic uncomplicated diverticular disease and the role of Rifaximin in management

Patients with diverticulosis who develop persistent abdominal pain, bloating and changes in bowel habits not associated with overt inflammation may have symptomatic uncomplicated diverticular disease (SUDD). The severity and frequency of SUDD symptoms may have an impact on daily activities and severely affect quality of life. Effective management of SUDD should follow a three part strategy: divert, tackle and maintain. Divert to make the correct diagnosis: several symptoms of SUDD are common to other conditions that require different therapeutic approaches. However, several key differences should be used to diagnose SUDD. Pain in SUDD is normally in the iliac fossa, persistent, often lasting more than 24 hrs, and is not relieved by bowel movement, as is often the case with irritable bowel syndrome. Another difference is in the timing: the prevalence of SUDD increases with age, and patients under the age of 40 years are less likely to have diverticula. It is useful to establish whether a patient has diverticulosis, especially if the patient is relatively young; lack of diverticula excludes SUDD. Cross-sectional imaging is indicated; however, recent archival image data or ultrasonography may be useful alternatives. Laboratory tests should be ordered to exclude overt inflammation. Once the diagnosis of SUDD is made, the patient should receive effective therapy to tackle the condition. This should include dietary fibre supplementation and cyclic treatment with rifaximin 400 mg twice daily for 7 days per month. Once symptom control is achieved, it should be maintained by continuing therapy for at least 12 months.

Increased risk for irritable bowel syndrome after acute diverticulitis

BACKGROUND & AIMS

Individuals with diverticulosis frequently also have irritable bowel syndrome (IBS), but there are no longitudinal data to associate acute diverticulitis with subsequent IBS, functional bowel disorders, or related emotional distress. In patients with postinfectious IBS, gastrointestinal disorders cause long-term symptoms, so we investigated whether diverticulitis might lead to IBS. We compared the incidence of IBS and functional bowel and related affective disorders among patients with diverticulitis.

METHODS

We performed a retrospective study of patients followed up for an average of 6.3 years at a Veteran's Administration medical center. Patients with diverticulitis were identified based on International Classification of Diseases, 9th revision codes, selected for the analysis based on chart review (cases, n = 1102), and matched with patients without diverticulosis (controls, n = 1102). We excluded patients with prior IBS, functional bowel, or mood disorders. We then identified patients who were diagnosed with IBS or functional bowel disorders after the diverticulitis attack, and controls who developed these disorders during the study period. We also collected information on mood disorders, analyzed survival times, and calculated adjusted hazard ratios.

RESULTS

Cases were 4.7-fold more likely to be diagnosed later with IBS (95% confidence interval [CI], 1.6-14.0; P = .006), 2.4-fold more likely to be diagnosed later with a functional bowel disorder (95% CI, 1.6-3.6; P < .001), and 2.2-fold more likely to develop a mood disorder (CI, 1.4-3.5; P < .001) than controls.

CONCLUSIONS

Patients with diverticulitis could be at risk for later development of IBS and functional bowel disorders. We propose calling this disorder postdiverticulitis IBS. Diverticulitis appears to predispose patients to long-term gastrointestinal and emotional symptoms after resolution of inflammation; in this way, postdiverticulitis IBS is similar to postinfectious IBS.

New strategies for the management of diverticular disease: insights for the clinician

Diverticulosis is one of the most common gastrointestinal conditions affecting the general population in the Western world. It is estimated that over 2.5 million people are affected by diverticular disease in the United States. The spectrum of clinical manifestations of diverticulosis ranges from asymptomatic diverticulosis to complicated diverticulitis. Treatment for symptomatic diverticular disease is largely based on symptoms. Traditional therapy includes fiber, bowel rest, antibiotics, pain control and surgery for selected cases. This review discusses recent advances in the medical treatment of diverticular disease such as the use of mesalamine, rifaximin and probiotics as our understanding of the disease evolves.

Diverticular disease as a chronic illness: evolving epidemiologic and clinical insights

Diverticular disease imposes a significant burden on Western and industrialized societies. The traditional pathogenesis model posits that low dietary fiber predisposes to diverticulosis, and fecalith obstruction prompts acute diverticulitis that is managed with broad-spectrum antibiotics or surgery. However, a growing body of knowledge is shifting the paradigm of diverticular disease from an acute surgical illness to a chronic bowel disorder composed of recurrent abdominal symptoms and considerable psychosocial impact. New research implicates a role for low-grade inflammation, sensory-motor nerve damage, and dysbiosis in a clinical picture that mimics irritable bowel syndrome (IBS) and even inflammatory bowel disease (IBD). Far from being an isolated event, acute diverticulitis may be the catalyst for chronic symptoms including abdominal pain, cramping, bloating, diarrhea, constipation, and "post-diverticulitis IBS." In addition, studies reveal lower health-related quality of life in patients with chronic diverticular disease vs. controls. Health-care providers should maintain a high index of suspicion for the multifaceted presentations of diverticular disease, and remain aware that it might contribute to long-term emotional distress beyond traditional diverticulitis attacks. These developments are prompting a shift in therapeutic approaches from widespread antimicrobials and supportive care to the use of probiotics, mesalamine, and gut-directed antibiotics. This review addresses the emerging literature regarding epidemiology, pathophysiology, and management of chronic, symptomatic diverticular disease, and provides current answers to common clinical questions.

Exogenous oxytocin reverses the decrease of colonic smooth muscle contraction in antenatal maternal hypoxia mice via ganglia

Oxytocin (OT) has been reported to have a potential protective effect on stress-induced functional gastrointestinal disorders. This study determined whether colonic contraction in adults was affected by antenatal maternal hypoxia, and whether OT is involved in antenatal maternal hypoxia induced colonic contraction disorder. Isometric spontaneous contractions were recorded in colonic longitudinal muscle strips in order to investigate colonic contractions and the effects of exogenous OT on the contraction in antenatal maternal hypoxia and control mice. Both high potassium and carbachol-induced contractions of proximal colon but not distal colon were reduced in antenatal maternal hypoxia mice. Exogenous OT decreased the contractions of proximal colonic smooth muscle strips in control mice, while it increased contractions in antenatal maternal hypoxia mice. OT increased the contractions of distal colonic smooth muscle strips in both antenatal maternal hypoxia and control mice. Hexamethonium blocked the OT-induced potentiation of proximal colon but not distal colon in antenatal maternal hypoxia mice. These results suggest that exogenous oxytocin reverses the decrease of proximal colonic smooth muscle contraction in antenatal maternal hypoxia mice via ganglia.

Abnormal colonic motility: a possible association with urge fecal incontinence

PURPOSE

Fecal incontinence is a distressing condition affecting up to 7% of the population. Severe urgency is a symptom associated with hypersensitivity of the rectum, a common finding in both fecal incontinence and irritable bowel syndrome. The purpose of this study was to investigate whether patients with fecal incontinence, urgency, and rectal hypersensitivity have abnormal hindgut motility, suggestive of a more generalized motility problem.

METHODS

Eleven females with urgency-associated incontinence and without anal sphincter injury were compared with 5 controls. After full clinical, ultrasonographic, and physiological assessment, patients underwent prolonged colonic manometry studies. Motility patterns were recorded and, in particular, the response to a standard gastrocolic reflex was noted.

RESULTS

Rectal sensation values in patients were as follows: first sensation, 22 (range, 5-58) mls; desire to defecate, 31 (range, 13-166) mls; and maximum tolerated volume, 64 (range, 21-254) mls. Compared with controls, patients had significantly higher numbers of 1) low amplitude waves (>5 mmHg) in both the sigmoid colon (101 vs 46.5; P = .028) and the descending colon (101.5 vs 41; P = .036) in the hour before the meal stimulus, and 2) high amplitude waves (>50 mmHg) in the sigmoid colon (2 vs 0; P = .006) in the fasting state.

CONCLUSION

Patients with fecal incontinence associated with severe urgency may have rectal hypersensitivity and a more global colonic motility problem similar to irritable bowel syndrome.

Heightened colon motor activity measured by a wireless capsule in patients with constipation: relation to colon transit and IBS

Relationships of regional colonic motility to transit in health, constipation, and constipation-predominant irritable bowel syndrome (C-IBS) are poorly characterized. This study aimed to 1) characterize regional differences in colon pressure, 2) relate motor differences in constipation to colon transit, and 3) quantify the role of IBS in altered contractility with constipation. Colon pH and pressure were measured by wireless capsules in 53 healthy and 36 constipated subjects. Numbers of contractions >25 mmHg and areas under curves (AUC) were calculated for colon transit quartiles by time. Constipation was classified as normal transit (<59 h), moderate slow transit (STC) (59-100 h), and severe STC (>100 h). Twelve out of 36 constipated subjects had C-IBS; 24 had functional constipation. Numbers of contractions and AUCs increased from the first to the fourth quartile in health (P < 0.0001). Mean numbers of contractions in constipated subjects were similar to controls. Mean AUCs with normal transit (P = 0.01) and moderate STC (P = 0.004) but not severe STC (P = NS) were higher than healthy subjects. IBS was associated with greater mean numbers of contractions (P = 0.05) and AUCs (P = 0.0006) vs. controls independent of transit. Numbers of contractions increased from the first to fourth quartiles in moderate STC, C-IBS, and functional constipation; AUCs increased from the first to fourth quartiles in all groups (all P < 0.05). In conclusion, colon pressure activity is greater distally than proximally in health. Constipated patients with normal or moderately delayed transit show increased motor activity that is partly explained by IBS. These findings emphasize differential effects on transit and motility in different constipation subtypes.

Peripheral factors in the pathophysiology of irritable bowel syndrome

The pathophysiology of IBS is complex and still incompletely known. Both central and peripheral factors are thought to contribute to the symptoms of IBS, including psychosocial factors, abnormal GI motility and secretion, and visceral hypersensitivity. In this review the involvement of peripheral factors in the pathophysiology in IBS is reviewed. Altered GI motility is commonly found in this patient group, even though a specific motor pattern has been hard to find. Colonic transit has been found to be of relevance for the bowel habit of the patient. Abnormal gas handling within the gut is also commonly seen, and seems to be one, but not the only factor responsive for bloating. There is also limited evidence supporting the presence of abnormal GI secretion in IBS, but its relevance for symptoms remains unclear. Visceral hypersensitivity is currently considered to be one of the most important pathophysiological factors in IBS. It can be modulated by several external and internal factors and recent studies support an association between colorectal sensitivity and the symptoms reported by the patients, especially pain.

New insights into the pathogenesis and pathophysiology of irritable bowel syndrome

The pathogenesis and pathophysiology of irritable bowel syndrome is complex and still incompletely known. Potential pathogenetic factors include genes, infectious events, psychological symptoms and other loosely defined environmental factors. Both alterations at the central and peripheral level are thought to contribute to the symptoms of irritable bowel syndrome, including psychosocial factors, abnormal gastrointestinal motility and secretion, and visceral hypersensitivity. Today irritable bowel syndrome is viewed upon as a disorder of dysregulation of the so-called brain-gut axis, involving abnormal function in the enteric, autonomic and/or central nervous systems, with peripheral abnormalities probably dominating in some patients and disturbed central processing of signals from the periphery in others. Lines of evidence also suggest that inflammation within the gastrointestinal tract may be of great importance in at least subgroups of irritable bowel syndrome patients. To conclude, a complex picture of the pathogenesis and pathophysiology of irritable bowel syndrome is emerging, with interactions between several different alterations resulting in the divergent symptom pattern in these patients.

Functional findings in irritable bowel syndrome

The pathophysiology of IBS is complex and still incompletely known. Both central and peripheral factors, including psychosocial factors, abnormal GI motility and secretion, and visceral hypersensitivity, are thought to contribute to the symptoms of IBS. Several studies have demonstrated altered GI motor function in IBS patients and the pattern differs between IBS subgroups based on the predominant bowel pattern. Few studies have so far addressed GI secretion in IBS, but there are some evidence supporting altered secretion in the small intestine of IBS patients. Visceral hypersensitivity is currently considered to be perhaps the most important pathophysiological factor in IBS. Importantly, several external and internal factors can modulate visceral sensitivity, as well as GI motility, and enhanced responsiveness within the GI tract to for instance stress and nutrients has been demonstrated in IBS patients. Today IBS is viewed upon as a disorder of dysregulation of the so-called brain-gut axis, involving abnormal function in the enteric, autonomic and/or central nervous systems, with peripheral alterations probably dominating in some patients and disturbed central processing of signals from the periphery in others.

New views on antidiarrheal effect of wood creosote: is wood creosote really a gastrointestinal antiseptic?

Wood creosote, the principal ingredient in Seirogan, has a long history as a known gastrointestinal microbicidal agent. When administered orally, the intraluminal concentration of wood creosote is not sufficiently high to achieve this microbicidal effect. Through further animal tests, we have shown that antimotility and antisecretory actions are the principal antidiarrheal effects of wood creosote. Wood creosote inhibits intestinal secretion induced by enterotoxins by blocking the Cl(-) channel on the intestinal epithelium. Wood creosote also decreases intestinal motility accelerated by mechanical, chemical, or electrical stimulus by the inhibition of the Ca(2+) influx into the smooth muscle cells. In this overview, the antimotility and antisecretory effects of wood creosote are compared with those of loperamide. Wood creosote was observed to inhibit stimulated colonic motility, but not normal jejunal motility. Loperamide inhibits normal jejunal motility, but not stimulated colonic motility. Both wood creosote and loperamide inhibit intestinal secretion accelerated by acetylcholine. Wood creosote was found to have greater antisecretory effects in the colon than loperamide. Based upon these findings, we conclude that the antidiarrheal effects of wood creosote are due to both antisecretory activity in the intestine and antimotility in the colon, but not due to the microbicidal activity as previously thought. Wood creosote was found to have no effects on normal intestinal activity. These conclusions are supported by the results of a recent clinical study comparing wood creosote and loperamide, which concluded that wood creosote was more efficacious in relieving abdominal pain and comparable to loperamide in relieving diarrhea.

Viscerosensory-cardiovascular reflexes: altered baroreflex sensitivity in irritable bowel syndrome

Animal studies have demonstrated that visceral afferent stimulation alters autonomic cardiovascular reflexes. This mechanism might play an important role in the pathophysiology of conditions associated with visceral hypersensitivity, such as irritable bowel syndrome (IBS). As such, studies in humans are lacking, we measured viscerosensory-cardiovascular reflex interactions in IBS patients and healthy controls. Systolic blood pressure (SBP), heart rate (HR), and arterial baroreflex sensitivity (BRS) were studied in 87 IBS patients and 36 healthy controls under baseline conditions and during mild (15 mmHg) and intense (35 mmHg) visceral stimulation by rectal balloon distension. BRS was computed from continuous ECG and arterial blood pressure signals (Finapres-method) during 5-min periods of 15-min metronome respiration. Baseline SBP and HR were not different between patients and controls. In both groups, SBP increased similarly during rectal stimulation, whereas HR decreased during mild and increased intense stimulation. BRS was significantly higher in patients compared with controls at baseline (7.9 +/- 5.4 vs. 5.7 +/- 3.7 ms/mmHg, P = 0.03) and increased significantly in both groups during mild stimulation. This increase persisted in controls during intense stimulation, but BRS returned to baseline in patients. BRS was not significantly different between groups during rectal distension. This study demonstrates the presence of a viscerosensory-cardiovascular reflex in healthy individuals and in IBS patients. The increased BRS in IBS patients at baseline may either be a training-effect (frequent challenging of the reflex) or reflects altered viscerosensory processing at the nucleus tractus solitarii.