Prevalence, investigational pathways and diagnostic outcomes in differing irritable bowel syndrome subtypes

Prevalence and Associated Dietary Factors of Rome IV Functional Gastrointestinal Disorders in Rural Western Honduras

BACKGROUND

The literature is limited regarding the prevalence of functional gastrointestinal disorders (FGIDs) in Central America, and the role of dietary factors.

METHODS

The Rome IV diagnostic questionnaire and National Cancer Institute Diet History questionnaire were administered in one-on-one interviews to a distributed cross section of the general adult population of Western Honduras. Our aim was to estimate prevalence of common FGIDs and symptoms and their relationships to dietary habits.

RESULTS

In total, 815 subjects were interviewed, of whom 151 fulfilled criteria for an FGID (18.5%). Gastroduodenal FGIDs were noted in 9.4%, with epigastric pain syndrome (EPS) more common than postprandial distress syndrome, 8.5% versus 1.6%. Among bowel disorders, functional abdominal bloating (FAB) was most prevalent (6.3%), followed by irritable bowel syndrome (3.6%), functional diarrhea (FDr; 3.4%), and functional constipation (1.1%). A significant inverse association was noted between regular bean intake and any FGID (OR 0.41, 95% CI 0.27-0.63), driven by IBS and FDr. Vegetable consumption was associated with lower prevalence of functional diarrhea (OR 0.12; 95% CI 0.04-0.35) and any diarrheal disorder (OR 0.11; 95% CI 0.04-0.31). Subjects with a median daily intake of ≥ 4 corn tortillas had 1.75 (95% CI 1.22-2.50) times the odds of having any FGID.

CONCLUSIONS

FGIDs were common in this rural low-resource setting in Central America, with an intriguing distribution of specific FGIDs. EPS and FAB were common, but IBS was not. Local dietary factors were associated with specific FGIDs, suggesting that diet may play a role in global variations of FGIDs.

Management of irritable bowel syndrome with diarrhea: focus on eluxadoline

OBJECTIVE

We sought to summarize current recommendations for the diagnosis of diarrhea-predominant irritable bowel syndrome (IBS-D) and describe available management options, highlighting a newer US Food and Drug Administration (FDA)-approved agent, eluxadoline.

METHODS

Literature on IBS-D was assessed up to January 2020 using PubMed, with key search terms including "IBS-D diagnosis", "IBS-D management", and "eluxadoline".

RESULTS

IBS is a common gastrointestinal disorder affecting up to 14% of US adults and is particularly prevalent in women and those aged under 50. Symptoms include abdominal pain associated with altered bowel habits (i.e. diarrhea and/or constipation subtyped based on the predominant stool pattern). As IBS-D is challenging to manage with varying symptom severity, effective treatment requires a personalized management approach. Evidence-based therapeutic options endorsed by the American Gastroenterological Association and the American College of Gastroenterology can be used to effectively guide treatment. Dietary and lifestyle modifications, including adequate hydration, reducing caffeine and alcohol intake, and increasing soluble fiber intake may lead to symptom improvement. Over-the-counter medications such as loperamide are frequently recommended and may improve stool frequency and rectal urgency; however, for the outcome of abdominal pain, mixed results have been observed. Several off-label prescription medications are useful in IBS-D management, including tricyclic antidepressants, bile acid sequestrants, and antispasmodics. Three prescription medications have been approved by the FDA for IBS-D: alosetron, eluxadoline, and rifaximin.

CONCLUSIONS

IBS-D can be effectively managed in the primary care setting in the absence of alarm features. Benefits and risks of pharmacologic interventions should be weighed during treatment selection.

Irritable Bowel Syndrome: News from an Old Disorder

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, which can affect all members of a society, regardless of age, sex, race or socioeconomic status. Because of its high prevalence and chronic nature, it represents a significant economic burden. In fact, these patients have a relevant impairment of their quality of life, which limits their work productivity and daily social activities, especially when it is associated with other disorders, such as anxiety and depression. The diagnosis of IBS relies on symptom-based diagnostic criteria with normal results on a limited number of complementary tests that rule out other possible diagnoses. The aetiology of this condition is incompletely established. However, evidence suggests that it is a multifactorial disorder with several different mechanisms that have been implicated as responsible for the symptoms. Since the treatment strategy is usually based on predominant symptoms and their severity, it is important to recognise the underlying mechanisms in order to successfully relief the visceral pain and altered bowel habits. The aim of this non-systematic review of the literature was to explore the pathophysiology and treatment options of IBS, highlighting the most recent evidence, from the new Rome IV criteria to the new drug armamentarium.

Effects of treatment with eluxadoline on abdominal pain in patients with IBS-D: Additional post hoc analyses of Phase 3 trials

BACKGROUND

Recurring abdominal pain is a characteristic and often unpredictable and debilitating symptom of irritable bowel syndrome with diarrhea (IBS-D). Measuring the effects of IBS-D treatments on abdominal pain remains a significant challenge in clinical trials. Here, we aimed to examine the effect of eluxadoline through various post hoc analyses.

METHODS

Data from two eluxadoline Phase 3 trials were pooled over 26 weeks, comparing eluxadoline 100 mg twice daily to placebo. Worst abdominal pain (WAP) was measured daily on a 0-10 scale. WAP responder criteria were prospectively defined as a ≥30% improvement in daily WAP score on ≥50% of days. Pairwise, two-sided Cochran-Mantel-Haenszel tests assessed treatment effects. Cumulative distribution functions were used to plot WAP response rates using variations on the response criteria.

KEY RESULTS

Of 1615 patients with IBS-D (66% female, mean age 46 years), 806 received eluxadoline and 809 received placebo; 48.3% and 44.0% were WAP responders (≥30% improvement), respectively (P value not significant). When the response threshold was increased to 50% daily WAP improvement from baseline, a significantly greater percentage of eluxadoline-treated patients versus placebo-treated patients were WAP responders (38.7% vs 32.5%, respectively; P = .009). At Week 26, average WAP changes from baseline were -3.4 and -3.0 points, respectively (P = .002).

CONCLUSIONS AND INFERENCES

Despite small effect sizes, eluxadoline demonstrated consistent and sustained improvement in WAP compared to placebo across a range of prospective and post hoc analyses. Assessing WAP response across a range of measures is important for fully understanding a treatment's efficacy.

Multicenter observational study on functional bowel disorders diagnosed using Rome III diagnostic criteria in Japan

BACKGROUND

The Rome III diagnostic criteria had been used to diagnose functional gastrointestinal disorders (FGIDs) world wide, and functional bowel disorders (FBDs) including irritable bowel syndrome (IBS) have recently attracted the attention of Japanese physicians. However, there have been few reports on the prevalence of FBDs diagnosed by the Rome III diagnostic criteria.

AIMS

The aim of this study was to determine the prevalence of FBDs diagnosed according to the diagnostic criteria of Rome III in Japan.

PATIENTS AND METHODS

All patients who were booked for colonoscopy were enrolled from eight institutions in Japan. This study was a prospective observational study in the period from April 2013 to December 2013. Patients filled out FGID questionnaires of Rome III when they were waiting for colonoscopy.

RESULTS

Data for 1200 patients who underwent colonoscopy were analyzed. A total of 547 patients (45.6%) were diagnosed with FBDs. Out of those patients, 9.1% had IBS. According to the Rome III diagnostic criteria, 134 patients (11.2%) had functional bloating (FB), 73 (6.1%) had functional constipation (FC), 40 (3.3%) had functional diarrhea (FD), and 191 (15.9%) had unspecified functional bowel disorder (UFBD). Patients with FBDs had significantly higher rates of almost all symptoms (abdominal pain, hard or lumpy stools, loose or watery stools, and bloating) than those in the controls.

CONCLUSIONS

In Japan, the prevalence of FBDs and IBS is high, similar to that in the US. Many patients with FBDs have multiple symptoms.

Psychiatric Co-morbidity in Patients With Irritable Bowel Syndrome at a Tertiary Care Center in Northern India

Background/Aims

Irritable bowel syndrome (IBS) is a chronic psycho-physiological disorder. It is considered to be the most common functional gastrointestinal disorder, and about 50–90% of IBS patients have associated psychiatric co-morbidity. We aimed to study psychiatric co-morbidities in patients with IBS visiting a tertiary care center.

Methods

This was a cross-sectional case-control study conducted over a duration of one and a half years from January 2014 to July 2015. Patients were selected from the out-patient department of gastroenterology. About 160 patients with IBS who fulfilled the inclusion criteria and who gave written informed consent were selected as study cases. The healthy attendants of cases were selected as controls. A total of 200 controls were selected. Rome-III criteria were used to diagnose IBS. For diagnosing psychiatric disorders, we used the Mini International Neuropsychiatric Interview Schedule Plus.

Results

Mean age of our cases and controls was 39.7 ± 11.4 and 37.7 ± 9.6 years, respectively. Females outnumbered males in our cases as well as their controls by a ratio of 2:1 approximately. Psychiatric disorders were seen in 84.4% of IBS patients as compared to 41.5% in controls. Major psychiatric disorders seen in our patients were generalized anxiety disorders (30.0%) and depression (28.0%).

Conclusions

The majority of patients with IBS who present to a tertiary care center have co-morbid psychiatric disorders. We need to screen these patients for such co-morbidities and develop a holistic approach for better outcome in such cases.

Irritable bowel syndrome subtypes: Clinical and psychological features, body mass index and comorbidities

BACKGROUND

Irritable bowel syndrome (IBS) is classified into subtypes according to bowel habit.

OBJECTIVE

To investigate whether there are differences in clinical features, comorbidities, anxiety, depression and body mass index (BMI) among IBS subtypes.

METHODS

The study group included 113 consecutive patients (mean age: 48 ± 11 years; females: 94) with the diagnosis of IBS. All of them answered a structured questionnaire for demographic and clinical data and underwent upper endoscopy. Anxiety and depression were assessed by the Hospital Anxiety and Depression scale (HAD).

RESULTS

The distribution of subtypes was: IBS-diarrhea (IBS-D), 46%; IBS-constipation (IBS-C), 32%, and mixed IBS (IBS-M), 22%. IBS overlap with gastroesophageal reflux disease (GERD), functional dyspepsia, chronic headache and fibromyalgia occurred in 65.5%, 48.7%, 40.7% and 22.1% of patients, respectively. Anxiety and/or depression were found in 81.5%. Comparisons among subgroups showed that bloating was significantly associated with IBS-M compared to IBS-D (odds ratio-OR-5.6). Straining was more likely to be reported by IBS-M (OR 15.3) and IBS-C (OR 12.0) compared to IBS-D patients, while urgency was associated with both IBS-M (OR 19.7) and IBS-D (OR 14.2) compared to IBS-C. In addition, IBS-M patients were more likely to present GERD than IBS-D (OR 6.7) and higher scores for anxiety than IBS-C patients (OR 1.2). BMI values did not differ between IBS-D and IBS-C.

CONCLUSION

IBS-M is characterized by symptoms frequently reported by both IBS-C (straining) and IBS-D (urgency), higher levels of anxiety, and high prevalence of comorbidities. These features should be considered in the clinical management of this subgroup.

Prevalence and risk factors for functional bowel disorders in South China: a population based study using the Rome III criteria

BACKGROUND

Functional bowel disorders (FBDs) such as irritable bowel syndrome (IBS) impact on quality of life and health care resources. It is uncertain whether patients with functional digestive symptoms have similar characteristics in different populations. This population-based study assessed the prevalence and identified risk factors for these disorders in South-East China.

METHODS

Five communities were selected at random and invitations distributed to a representative sample (block randomization). Questionnaires were completely supervised by investigators. Demographic and medical data with FBD symptoms (Rome III criteria), psychological condition, life event stress, and quality of life were collected.

KEY RESULTS

Functional bowel disorder prevalence was 41.6% in 1999/2115 (94.5%) completed questionnaires: 9.9% functional constipation (FC), 6.8% bloating (FB), 6.5% diarrhea (FD), 5.9% IBS (IBS-D 47.1%, IBS-M 23.9%, IBS-C 12.8%, IBS-U 16.2%), and 12.6% unspecified. Similar numbers of men and women had FBDs or IBS (overall; 51.3% male vs 48.7% female, P=.796); however, there was female predominance in FC (62.1%, P<.001) and FB (58.5%, P=.038). FBDs were associated with greater anxiety, depression, life event stress, and a lower quality of life compared with those without symptoms (all, P<.0001). Logistic regression identified medical co-morbidity, anxiety/depression, and life event stress as independent risk factors for these disorders.

CONCLUSIONS & INFERENCES

Functional bowel disorders are as common in South China as in western populations. A similar number of men and women report FBDs and IBS. Only FC and FB are more prevalent in females. Independent risk factors associated with FBDs included physical and psychosocial stressors.

Ameliorative effects of atractylodin on intestinal inflammation and co-occurring dysmotility in both constipation and diarrhea prominent rats

Intestinal disorders often co-occur with inflammation and dysmotility. However, drugs which simultaneously improve intestinal inflammation and co-occurring dysmotility are rarely reported. Atractylodin, a widely used herbal medicine, is used to treat digestive disorders. The present study was designed to characterize the effects of atractylodin on amelioration of both jejunal inflammation and the co-occurring dysmotility in both constipation-prominent (CP) and diarrhea-prominent (DP) rats. The results indicated that atractylodin reduced proinflammatory cytokines TNF-α, IL-1β, and IL-6 in the plasma and inhibited the expression of inflammatory mediators iNOS and NF-kappa B in jejunal segments in both CP and DP rats. The results indicated that atractylodin exerted stimulatory effects and inhibitory effects on the contractility of jejunal segments isolated from CP and DP rats respectively, showing a contractile-state-dependent regulation. Atractylodin-induced contractile-state-dependent regulation was also observed by using rat jejunal segments in low and high contractile states respectively (5 pairs of low/high contractile states). Atractylodin up-regulated the decreased phosphorylation of 20 kDa myosin light chain, protein contents of myosin light chain kinase (MLCK), and MLCK mRNA expression in jejunal segments of CP rats and down-regulated those increased parameters in DP rats. Taken together, atractylodin alleviated rat jejunal inflammation and exerted contractile-state-dependent regulation on the contractility of jejunal segments isolated from CP and DP rats respectively, suggesting the potential clinical implication for ameliorating intestinal inflammation and co-occurring dysmotility.

Elevated Circulating hsa-miR-106b, hsa-miR-26a, and hsa-miR-29b in Type 2 Diabetes Mellitus with Diarrhea-Predominant Irritable Bowel Syndrome

Background and Aims. Although the differential expression of microRNA (miRNA) genes has been identified in many diseases, little information exists concerning the miRNA expression profile in type 2 diabetes mellitus (T2DM) with diarrhea-predominant irritable bowel syndrome (D-IBS). Therefore, the specific expression of miRNAs in diabetes with D-IBS is identified in the study. Materials and Methods. 201 patients with IBS and 220 matched healthy controls were included in the study. Microarray technology and real-time reverse transcriptase-polymerase chain reaction analysis (RT-PCR) were taken to examine the miRNA expression profiles of T2DM patients with diarrhea-predominant irritable bowel syndrome (D-IBS) compared with patients with T2DM, patients with D-IBS, and control subjects. Results. We have found that 35 miRNAs were differentially expressed in T2DM with D-IBS, in which three representative miRNAs, hsa-miR-106b, hsa-miR-26a, and hsa-miR-29b, were found to be significantly elevated in T2DM with D-IBS by RT-PCR. Conclusions. Our study has indicated that hsa-miR-106b, hsa-miR-26a, and hsa-miR-29b were elevated in T2DM with D-IBS, which may be the potential biomarkers of T2DM with D-IBS. To obtain a better understanding of the biological functions of these miRNAs in T2DM with D-IBS, functional annotation analysis suggested that the MAPK pathway may be responsible for T2DM with D-IBS.

New and emerging therapies for the treatment of irritable bowel syndrome: an update for gastroenterologists

Irritable bowel syndrome is a functional bowel disorder with gastrointestinal symptoms (e.g. abdominal pain, straining, urgency, incomplete evacuation, nausea, and bloating) that occur alongside bowel function alterations (i.e. constipation, diarrhea, or both). Patients with irritable bowel syndrome may also experience comorbid anxiety and depression. Irritable bowel syndrome is common, with a prevalence estimated between 3% and 28%, affecting patient health and quality of life. Patients with moderate or severe irritable bowel syndrome generally seek medical care, whereas those with milder symptoms may choose self-management. Most patients with irritable bowel syndrome receive outpatient care, but irritable bowel syndrome-related hospitalizations do occur. The pathophysiology of irritable bowel syndrome is multifactorial (i.e. genetics, immune components, changes in the gut microbiota, disturbances in physiologic stress response systems, and psychosocial factors). Management of irritable bowel syndrome can include lifestyle changes, dietary interventions, counseling, psychologic medication, and agents that affect gastrointestinal motility. A number of therapies have emerged in recent years with clinical trial data demonstrating efficacy and safety for patients with irritable bowel syndrome, including agents that target gastrointestinal motility (i.e. linaclotide), gastrointestinal opioid receptors (i.e. asimadoline, eluxadoline), and gut microbiota (i.e. rifaximin). Linaclotide has been shown to significantly improve stool frequency and abdominal pain compared with placebo in constipation-predominant irritable bowel syndrome (number needed to treat, 5.1). Asimadoline shows efficacy in patients with moderate-to-severe irritable bowel syndrome-related pain. Rifaximin provided adequate relief of global irritable bowel syndrome symptoms versus placebo for a significantly greater percentage of patients with diarrhea-predominant irritable bowel syndrome (p < 0.001). Management that encompasses all aspects of irritable bowel syndrome (gastrointestinal symptoms) and comorbid psychologic symptoms (e.g. anxiety or depression) is important for improving overall patient health and well-being.

Efficacy of a Gluten-Free Diet in Subjects With Irritable Bowel Syndrome-Diarrhea Unaware of Their HLA-DQ2/8 Genotype

BACKGROUND & AIMS

A gluten-containing diet alters bowel barrier function in patients with irritable bowel syndrome with diarrhea (IBS-D), particularly those who are positive for HLA allele DQ2/8. We studied the effects of a gluten-free diet (GFD) in patients with IBS-D who have not previously considered the effects of gluten in their diet and were unaware of their HLA-DQ2/8 genotype.

METHODS

We performed a prospective study of 41 patients with IBS-D (20 HLA-DQ2/8-positive and 21 HLA-DQ2/8-negative) at the Royal Hallamshire Hospital in Sheffield, United Kingdom, from September 2012 through July 2015. All subjects were placed on a 6-week GFD following evaluation by a dietician. Subjects completed validated questionnaires at baseline and Week 6 of the GFD. The primary endpoint was mean change in IBS Symptom Severity Score; a 50-point reduction was considered to indicate a clinical response. Secondary endpoints were changes in hospital anxiety and depression score, fatigue impact score, and Short Form-36 results. Clinical responders who chose to continue a GFD after the study period were evaluated on average 18 months later to assess diet durability, symptom scores, and anthropometric and biochemical status.

RESULTS

A 6-week GFD reduced IBS Symptom Severity Score by ≥50 points in 29 patients overall (71%). The mean total IBS Symptom Severity Score decreased from 286 before the diet to 131 points after 6 weeks on the diet (P < .001); the reduction was similar in each HLA-DQ group. However, HLA-DQ2/8-negative subjects had a greater reduction in abdominal distention (P = .04). Both groups had marked mean improvements in hospital anxiety and depression scores, fatigue impact score, and Short Form-36 results, although HLA-DQ2/8-positive subjects had a greater reduction in depression score and increase in vitality score than HLA-DQ2/8-negative subjects (P = .02 and P = .03, respectively). Twenty-one of the 29 subjects with a clinical response (72%) planned to continue the GFD long term; 18 months after the study they were still on a GFD, with maintained symptom reductions, and demonstrated similar anthropometric and biochemical features compared with baseline.

CONCLUSIONS

A dietitian-led GFD provided sustained benefit to patients with IBS-D. The symptoms that improved differed in magnitude according to HLA-DQ status. Clinical trials.gov no: NCT02528929.

Alterations in serotonin metabolism in the irritable bowel syndrome

BACKGROUND

Alterations in serotonin (5-HT) metabolism have been postulated to play a role in the pathogenesis of irritable bowel syndrome (IBS). However, previous reports regarding 5-HT metabolism in IBS are contradicting.

AIM

To compare platelet poor plasma (PPP) 5-HT and 5-hydroxyindole acetic acid (5-HIAA) levels and their ratio in a large cohort of IBS patients and healthy controls (HC), including IBS-subgroup analysis.

METHODS

Irritable bowel syndrome patients and HC were evaluated for fasting PPP 5-HT and 5-HIAA levels. Furthermore, GI-symptom diary, GSRS, quality of life, anxiety and depression scores were assessed in the 2 weeks before blood sampling.

RESULTS

One hundred and fifty four IBS patients and 137 HC were included. No differences were detected in plasma 5-HT between groups. The 5-HIAA concentrations and 5-HIAA/5-HT ratio were significantly lower in IBS compared to HC: 24.6 ± 21.9 vs. 39.0 ± 29.5 μg/L (P < 0.001) and 8.4 ± 12.2 vs. 13.5 ± 16.6 (P < 0.01), respectively. Subtype analysis for 5-HIAA showed all IBS subtypes to be significantly different from HC. The 5-HIAA/5-HT ratio was significantly lower in the IBS-M subtype vs. HC. Linear regression analysis points to an influence of gender but not of GI-symptoms, psychological scores or medication use.

CONCLUSIONS

We demonstrated that fasting 5-HT plasma levels are not significantly different in IBS patients compared to controls. However, decreased 5-HIAA levels and 5-HIAA/5-HT ratio in IBS patients may reflect altered serotonin metabolism in IBS. Gender affects 5-HIAA levels in IBS patients, but no effects of drugs, such as SSRIs, or higher GI-symptom or psychological scores were found.

Burden of irritable bowel syndrome in an increasingly cost-aware National Health Service

BACKGROUND

The National Health Service (NHS) is faced with increasing cost pressures that make the efficient use of resources paramount. Irritable bowel syndrome (IBS) places a large burden on the NHS as it has been estimated that at least 12% of the UK population is affected. However, poor clinical coding makes accurate assessment of this burden challenging.

OBJECTIVE

To calculate primary-care prescribing and both hospital outpatient and admission costs associated with the management of IBS in England.

DESIGN AND MAIN OUTCOME MEASURES

Hospital Episode Statistics data for 2012-2013 for all clinical commissioning groups in England were analysed to calculate the tariff cost of IBS. Prescribing analysis and cost tabulation (PACT) data for this period were also analysed.

RESULTS

In 2012-2013, there were 1 219 961 outpatient attendances in gastroenterology and colorectal surgery specialties. Despite this, only 1982 patients were recorded with IBS-specific codes, with a total estimated tariff cost of £812 336. In addition, 28 849 patients were recorded with IBS-related symptom codes at a cost of £11 002 874. In 2011-2012, there were 658 698 diagnostic lower gastrointestinal endoscopies at a tariff cost of £16 967 670 4. Of these, 323 752 (49%) had no further follow-up in secondary care over the subsequent 12 months. PACT data indicated that £44 977 959 and £25 582 752, respectively, were spent on selected laxatives and antispasmodics commonly used to treat IBS in primary care.

CONCLUSIONS

Better diagnosing, through improved clinical coding and standardisation of diagnostic criteria, is required to more accurately assess the true burden and allow optimal management of IBS.

Epidemiology of Functional Gastrointestinal Disorders in Japan and in the World

Functional gastrointestinal disorders (FGIDs), represented by functional dyspepsia (FD) and irritable bowel syndrome (IBS), are a group of disorders that include variable combinations of chronic or recurrent gastrointestinal symptoms not explained by structural or biochemical abnormalities. FGIDs account for a significant percentage of patients seen in primary care settings with abdominal symptoms. Although the definition of FGIDs can easily affect the prevalence, the prevalences of dyspepsia/FD and IBS diagnosed by the Rome III criteria in the general population are 5.3–20.4% and 1.1–29.2%, respectively. Recent reports of FD and IBS defined by the Rome III criteria indicated a female predominance. Regarding the subtype prevalence of FD, postprandial distress syndrome was more prevalent than epigastric pain syndrome (5.6–13.9% vs 0.9–9.5%). The subtype prevalence of IBS is characterized by male predominance for IBS with diarrhea and female predominance for IBS with constipation. Factors affecting the development of FGIDs such as epidemiological factors including genetic and environmental factors, are important. Gene polymorphisms are involved in the development of FGIDs. The prevalence differs among races and geographic areas. Foods may affect the development of FGIDs, but the causal relationships between food and FGIDs are not conclusive. The symptoms often regress and appear in the course of these entities. Building a favorable patient-doctor relationship is effective for controlling symptoms of FGIDs. Physicians should explain that FGIDs are highly prevalent conditions, impair the patients’ quality of life even without evident underlying organic causes and are not life-threatening conditions to ensure patients’ understanding.