Diagnostic Yield of Colonoscopy in Patients With Symptoms Compatible With Rome IV Functional Bowel Disorders.

BACKGROUND & AIMS: There is little data on the diagnostic yield of colonoscopy in patients with symptoms compatible with functional bowel disorders (FBDs). Previous studies have only focused on diagnostic outcomes of colonoscopy in those with suspected irritable bowel syndrome using historic Rome I-III criteria, whilst having partially assessed for alarm features and shown markedly conflicting results. There is also no colonoscopy outcome data for other FBDs, such as functional constipation or functional diarrhea. Using the contemporaneous Rome IV criteria we determined the diagnostic yield of colonoscopy in patients with symptoms compatible with a FBD, stratified diligently according to the presence or absence of alarm features. METHODS: Basic demographics, alarm features, and bowel symptoms using the Rome IV diagnostic questionnaire were collected prospectively from adults attending out-patient colonoscopy in 2019. Endoscopists were blinded to the questionnaire data. Organic disease was defined as the presence of inflammatory bowel disease, colorectal cancer, or microscopic colitis. RESULTS: 646 patients fulfilled symptom-based criteria for the following Rome IV FBDs: IBS (56%), functional diarrhea (27%) and functional constipation (17%). Almost all had alarm features (98%). The combined prevalence of organic disease was 12%, being lowest for functional constipation and IBS-constipation (∼6% each), followed by IBS-mixed (∼9%), and highest amongst functional diarrhea and IBS-diarrhea (∼17% each); p = .005. The increased prevalence of organic disease in diarrheal versus constipation disorders was accounted for by microscopic colitis (5.7% vs. 0%, p < .001) but not inflammatory bowel disease (7.2% vs. 4.0%, p = .2) or colorectal cancer (4.2% vs. 2.3%, p = .2). However, 1-in-4 chronic diarrhea patients - conceivably at risk for microscopic colitis - did not have colonic biopsies taken. Finally, only 11 of 646 (2%) patients were without alarm features, in whom colonoscopy was normal. CONCLUSIONS: Most patients with symptoms of FBDs who are referred for colonoscopy have alarm features. The presence of organic disease is significantly higher in diarrheal versus constipation disorders, with microscopic colitis largely accounting for the difference whilst also being a missed diagnostic opportunity. In those patients without alarm features, the diagnostic yield of colonoscopy was nil.

Increased psychological distress and somatization in patients with irritable bowel syndrome compared with functional diarrhea or functional constipation, based on Rome IV criteria.

BACKGROUND: The Rome IV criteria for disorders of gut-brain interaction define irritable bowel syndrome (IBS) as a functional bowel disorder associated with frequent abdominal pain of at least 1 day per week. In contrast, functional diarrhea (FD) and functional constipation (FC) are relatively painless. We compared differences in mood and somatization between Rome IV IBS and FC/FD. METHODS: A total of 567 patients with Rome IV defined IBS or FD/FC completed a baseline questionnaire on demographics, abdominal pain frequency, mood (hospital anxiety and depression scale, HADS), and somatization (patient health questionnaire, PHQ-12). The primary analysis compared differences in mood and somatization between IBS and FC/FD, and the relative influence of abdominal pain frequency on these extra-intestinal symptoms. The secondary analysis evaluated differences across individual IBS subtypes, and also between FC and FD. KEY RESULTS: Patients with IBS-in comparison to those with FC/FD-had significantly higher mean PHQ-12 somatization scores (9.1 vs. 5.4), more somatic symptoms (6.0 vs. 4.3), abnormally high somatization levels (16% vs. 3%), higher HADS score (15.0 vs. 11.7), and clinically abnormal levels of anxiety (38% vs. 20%) and depression (17% vs. 10%). Increasing abdominal pain frequency correlated positively with PHQ-12, number of somatic symptoms, and HADS; p < 0.001. No differences in mood and somatization scores were seen between individual IBS subtypes, and nor between FC and FD. CONCLUSION & INFERENCES: Based on the Rome IV criteria, IBS is associated with increased levels of psychological distress and somatization compared with FD or FC. Patients reporting frequent abdominal pain should be comprehensively screened for psychosomatic disorders, with psychological therapies considered early in the disease course.