75SeHCAT in the assessment of improved bile acid absorption in patients with ileal damage by delaying bowel motility with loperamide

Abstract

Objective: To assess the effect of loperamide on bile acid malabsorption by delaying bowel motility, and its role in improving chronic diarrhoea in patients with deal damage due to radiation and/or resection. Design: Changes in bile acid absorption in relation to clinical response were prospectively studied after administration of loperamide in 19 patients with chronic diarrhoea due to deal irradiation and/or resection. Methods: Bile acid absorption was measured by sequential abdominal retention measurements and scintigraphic images using selenium-75 homocholic acid conjugated with taurine (75SeHCAT) before (baseline) and during administration of loperamide. Intervention: Oral administration of loperamide began 2 days before the beginning of the 75SeHCAT test and continued during the test (standard dose, 2 mg twice daily; in patients with extensive resection, 2 mg four times daily). Other medication (e.g. cholestyramine, aluminum hydroxide) was discontinued during loperamide administration. Results: In 13 patients (seven with ileal resection varying from 20–50cm and six without resection), 75SeHCAT retention either normalized or improved considerably, scintigraphic imaging showed recovery of absorption and recirculation of 75SeHCAT; symptomatic relief was observed in all cases. In six patients with an ileal resection greater than 80cm, 75SeHCAT retention remained abnormal and no changes in 75SeHCAT absorption were observed; three of these patients reported slight improvement of diarrhoea. Conclusion: In patients with limited ileal damage, the delaying effect of loperamide on bowel motility improves bile acid absorption and diarrhoea can be treated adequately with loperamide alone. In patients with extensive ileal damage, additional medication (e.g. cholestyramine) is required. The 75SeHCAT test with loperamide is helpful and easy to perform; however, additional 75SeHCAT imaging is essential for the interpretation of changes in the retention measurements.