Some patients with irritable bowel syndrome may have exocrine pancreatic insufficiency.

Background & Aims: Patients with irritable bowel syndrome (IBS) might have other underlying pathologies. Pancreatic disease can be elusive-especially in the early stages, and some symptoms overlap with those of IBS. We evaluated the prevalence of exocrine pancreatic insufficiency in diarrhea-predominant IBS (D-IBS) and assessed the effects of pancreatic enzyme supplementation.

Methods: The study included patients who met the Rome II criteria for D-IBS, patients with chronic diarrhea, and subjects without diarrhea (controls). Subjects' baseline weight, stool frequency, stool consistency (using the Bristol score), and fecal elastase-1 (Fel-1) levels were determined. Patients were assessed using British Society of Gastroenterology IBS guidelines. Patients with Fel-1 levels less than 100 microg/g stool (indicating pancreatic exocrine insufficiency; group 1) were compared with age- and sex-matched patients with D-IBS and normal levels of Fel-1 (group 2), given pancreatic enzyme therapy, and reassessed at 12 weeks.

Results: Fel-1 levels were less than 100 microg/g in stool from 19 of 314 patients with D-IBS (6.1%; 95% confidence interval [CI], 3.7%-9.3%), none of the 105 patients with chronic diarrhea (95% CI, 0.0%-3.5%), and none of 95 controls (95% CI, 0.0-3.8%) (P < .001). After enzyme supplementation, improvements in stool frequency (P < .001), stool consistency (P < .001), and abdominal pain (P = .003) were observed in patients in group 1, but not in group 2.

Conclusions: Pancreatic exocrine insufficiency was detected in 6.1% of patients who fulfilled the Rome II criteria for D-IBS. In these patients, pancreatic enzyme therapy might reduce diarrhea and abdominal pain. Pancreatic exocrine insufficiency should be considered in patients with D-IBS.