Similarities in Clinical and Psychosocial Characteristics of Functional Diarrhea and Irritable Bowel Syndrome With Diarrhea

Abstract

Background & aims: There have been few published studies of clinical and psychological characteristics of patients with functional diarrhea (FDr). We studied the clinical and psychological characteristics of patients with FDr presenting to a tertiary care clinic, and compared symptom profiles of FDr with those of IBS-diarrhea (IBS-D).

Methods: Consecutive patients with a diagnosis of FDr (n = 48) or IBS-D (n = 49), per Rome IV criteria, completed a detailed symptom survey from October 2017 through July 2018. Abdominal pain and diarrhea severity were assessed using patient-reported outcomes measurement information system (PROMIS) questionnaires. Patients with anxiety, depression, or sleep disturbances were identified based on PROMIS T-score of 60 or more. Mean and proportions were compared using the Student t test and chi-square analyses, respectively.

Results: A significantly lower proportion of patients with FDr reported abdominal pain (77.1%) than patients with IBS-D (100%, P < .001). The proportion of patients reporting abdominal bloating and level of severity did not differ significantly between groups. Proportions of bowel movements with diarrhea did not differ significantly between groups (P = .54), but the mean diarrhea PROMIS T-score was significantly higher among patients with IBS-D (P = .03). This difference resulted from the significantly higher levels of fecal urgency-related distress reported by patients with IBS-D (P = .007). Proportions of patients with anxiety, depression, or sleep disturbance, and their severities, did not differ significantly between groups.

Conclusions: In an analysis of about 100 patients with FDr or IBS-D, we found overlap in gastrointestinal and psychosomatic symptoms. These 2 entities appear to be a continuum.

Keywords: Bristol Stool Form Scale; Chronic Diarrhea; Healthcare Utilization; Somatization.