Bile acid malabsorption in persistent diarrhoea

We have investigated bile acid malabsorption (BAM), and its response to treatment, in patients seen in this district general hospital with chronic continuous or recurrent diarrhoea.

Seven-day retention of 75-SeHCAT was measured (normal: > 10%).

Patients were initially given conventional therapy (prednisolone +/- ASA drugs in Crohn's disease, and antidiarrhoeals in the others). If this therapy failed, bile acid sequestrants (BAS) were prescribed. The definition of successful response was based on the patient's perception of sustained improvement.

The 304 patients were categorised as follows: Group 1: Crohn's disease patients with ileal resection, in clinical remission (n = 37). Group 2: Crohn's disease, unoperated and in clinical remission (n = 44). Group 3: vagotomy and pyloroplasty, with/without cholecystectomy (n = 26). Group 4: diarrhoea predominant 'irritable bowel syndrome' (IBS) (n = 197).

BAM was found in 97% (36/37), 54% (24/44) and 58% (15/26) of patients in groups 1, 2 and 3 respectively. One third (65/197) of patients with IBS had BAM. The outcome of treatment was available in 96 patients with BAM: of the patients with ileal resection 32% responded to antidiarrhoeals, 60% to BAS. Of the unoperated Crohn's patients 55% responded to disease-specific therapy, 40% to BAS. Of the gastric surgery patients 18% responded to conventional treatment, 64% to BAS. Of the IBS patients 15% of responded to conventional therapy, 70% to BAS.

This observational study indicates that BAM is common in patients with chronic diarrhoea, and is frequently found in IBS. The results of open treatment suggest that, where antidiarrhoeal drugs fail in such patients, BAS are often effective.