Disturbed bowel habits in patients with non-ulcer dyspepsia

What Causes Functional Gastrointestinal Disorders? A Proposed Disease Model

Chronic unexplained gastrointestinal symptoms impact more than 1 in 5 Americans and their families; these disorders include the irritable bowel syndrome (IBS) and functional dyspepsia (FD), currently classified by Rome IV as functional gastrointestinal disorders. By definition, IBS and FD have no established pathology, but emerging evidence suggests this paradigm may need revision. Immune activation and, in subsets, subtle intestinal pathology have been identified in FD (most notably, postprandial distress syndrome) and IBS-diarrhea. A disease model is proposed that accounts for all of the intestinal and extraintestinal symptoms, relationship to food and infection, and the overlap with gastroesophageal reflux disease. It is speculated that antigen presentation to the mucosa (e.g., microbial antigens or food proteins after acute gastroenteritis) induces, in a genetically primed host, immune activation of the intestine with low-grade intestinal inflammation and subsequently neuronal structural and functional alterations, producing regional intestinal hypersensitivity and motor dysfunction. Immune activation may explain the female predominance and fluctuations in immune activity for symptom variability over time. In the future, as further evidence accumulates, the management paradigm may potentially shift to objective pathology-based subtyping based on serological, microbiological, and clinical assessments to identify when targeted therapies should be deployed in subsets. Potential targeted interventions may include therapies to dampen down immune activation or block release of key mediators such as histamine, specific microbial targeted treatments that may reverse disease, and dietary advice to eliminate relevant food antigens after objective in vivo testing. Only by identifying causation can we eventually anticipate cure, and as the true pathology unravels in subsets, this may become a reality.

Overlap of Irritable Bowel Syndrome and Functional Dyspepsia in the Clinical Setting: Prevalence and Risk Factors

BACKGROUND

According to Rome IV criteria, functional dyspepsia (FD) and irritable bowel syndrome (IBS) are distinct functional gastrointestinal disorders (FGID); however, overlap of these conditions is common in population-based studies, but clinical data are lacking.

AIMS

To determine the overlap of FD and IBS in the clinical setting and define risk factors for the overlap of FD/IBS.

METHODS

A total of 1127 consecutive gastroenterology outpatients of a tertiary center were recruited and symptoms assessed with a standardized validated questionnaire. Patients without evidence for structural or biochemical abnormalities as a cause of symptoms were then categorized based upon the symptom pattern as having FD, IBS or FD/IBS overlap. Additionally, this categorization was compared with the clinical diagnosis documented in the integrated electronic medical records system.

RESULTS

A total of 120 patients had a clinical diagnosis of a FGID. Based upon standardized assessment with a questionnaire, 64% of patients had FD/IBS overlap as compared to 23% based upon the routine clinical documentation. In patients with severe IBS or FD symptoms (defined as symptoms affecting quality of life), the likelihood of FD/IBS overlap was substantially increased (OR = 3.1; 95%CI 1.9-5.0) and (OR = 9.0; 95%CI 3.5-22.7), respectively. Thus, symptom severity for IBS- or FD symptoms were significantly higher for patients with FD/IBS overlap as compared to patients with FD or IBS alone (p all < 0.01). Age, gender and IBS-subtype were not associated with overlap.

CONCLUSION

In the clinical setting, overlap of FD and IBS is the norm rather than the exception. FD/IBS overlap is associated with a more severe manifestation of a FGID.

Clinical characteristics of functional dyspepsia depending on chemosensitivity to capsaicin

BACKGROUND

Augmented chemosensitivity to capsaicin has been demonstrated in approximately half of functional dyspepsia (FD) patients.

AIM

We determined clinical characteristics of FD patients with and without chemical hypersensitivity at baseline and after capsaicin ingestion for 4 weeks.

METHODS

N=49 outpatients with confirmed FD received an oral sensitivity test with 0.75 mg capsaicin at three occasions, before and after ingesting 0.25 mg capsaicin tid for 4 weeks. Symptomatic response to capsaicin allowed stratification to a capsaicin positive (chemosensitive) and a capsaicin negative (not chemosensitive) patient group. Symptom diaries were completed in the week before and during capsaicin ingestion.

RESULTS

A total of 53% FD had a positive capsaicin test, Crohnbach alpha was 0.85. Basic clinical characteristics were comparable in capsaicin positive and negative FD, but median daily aggregate upper gastrointestinal symptoms scores were significantly higher in capsaicin positive (median: 9.4; 5.4/11.7) than in capsaicin negative patients (6.6; 4.1/8.1) (P<.05). After capsaicin ingestion, upper gastrointestinal symptoms scores were reduced by -3.3 (-4.9/-1.9; P<.001) in capsaicin positive and -2.6 (-3.8/-0.3; P<.05) in capsaicin negative patients. Lower abdominal symptoms were comparable in capsaicin positive and negative patients at baseline (NS). After capsaicin ingestion lower gastrointestinal symptoms scores were reduced by -1.0 (-1.8/-0.1; P<.05) in capsaicin positive but not significantly altered (-0.6; -1.7/+0.9; NS) in capsaicin negative patients. After long-term capsaicin ingestion, the capsaicin test turned negative in 53% of chemosensitive patients (P<.01).

CONCLUSIONS

Differences in upper GI symptoms distinguished capsaicin positive and negative patients. Symptom improvement after long-term capsaicin ingestion was indirect proportional to the capsaicin test result.

Evidence-based clinical practice guidelines for functional dyspepsia

General interest in functional gastrointestinal disorders is increasing among Japanese doctors as well as patients. This increase can be attributed to a number of factors, including recent increased interest in quality of life and advances in our understanding of the pathophysiology of gastrointestinal disease. Japan recently became the world's first country to list "functional dyspepsia" as a disease name for national insurance billing purposes. However, recognition and understanding of functional dyspepsia (FD) remain poor, and no standard treatment strategy has yet been established. Accordingly, the Japanese Society of Gastroenterology (JSGE) developed an evidence-based clinical practice guideline for FD, consisting of five sections: concept, definition, and epidemiology; pathophysiology; diagnosis; treatment; and prognosis and complications. This article summarizes the Japanese guideline, with particular focus on the treatment section. Once a patient is diagnosed with FD, the doctor should carefully explain the pathophysiology and benign nature of this condition, establish a good doctor-patient relationship, and then provide advice for daily living (diet and lifestyle modifications, explanations, and reassurance). The proposed pharmacological treatment is divided into two steps: initial treatment including an acid inhibitory drug (H2RA or PPI) or prokinetics, (strong recommendation); second-line treatment including anxiolytics, antidepressants, and Japanese traditional medicine (weak recommendation). H. pylori eradication, strongly recommended with a high evidence level, is positioned separately from other treatment flows. Conditions that do not respond to these treatment regimens are regarded as refractory FD. Patients will be further examined for other organic disorders or will be referred to specialists using other approaches such as psychosomatic treatment.

Value of different diagnostic criteria for the irritable bowel syndrome among men and women

INTRODUCTION

Whether the diagnostic value of various criteria used to diagnose irritable bowel syndrome (IBS) differ by sex is controversial.

AIM

To evaluate the sex-specific value of varying IBS criteria and sex-specific symptoms in patients with IBS and organic disease.

METHODS

Outpatients of a gastroenterology practice (64% female) completed a validated questionnaire and received a complete diagnostic work-up as required. Questionnaire data were collected prospectively and audited retrospectively.

RESULTS

Overall 233 (male 21%) had a final diagnosis of IBS; 305 (male 47%) received a diagnosis of organic disease. Constipation and bloating were more frequent in females independent whether they had IBS or organic disease. The sensitivity of the diagnostic criteria in male patients was between 82% and 88%, when Manning (3 or more), Rome I or Rome II criteria were applied, whereas the specificity was 65% to 71%. In females, sensitivity was 62% to 64% and specificity was between 66% and 70%. Although all the diagnostic IBS criteria had higher positive predictive values in females versus males, the negative predictive values were lower in females.

CONCLUSIONS

Current criteria for IBS differ modestly between sexes, probably reflecting variable prevalence of the disease rather than a sex-specific presentation of IBS.