Objective: To evaluate whether a low dose of oral cholestyramine improves gallbladder emptying in gallstone patients.
Methods: Gallbladder volumes were assessed by sonography in 36 patients with cholesterol gallstones and 18 healthy controls. On three different days subjects ingested: 1) test meal alone, 2) test meal plus cholestyramine (4 g), and 3) cholestyramine alone (4 g).
Results: Fasting gallbladder volume (mean +/- SE, 25.9 +/- 1.8 ml and 19.2 +/- 1.3 ml for patients and controls, respectively, p < 0.05) and postprandial gallbladder residual volume (48.7 +/- 3.9% and 21.6 +/- 2.8% of fasting volume in patients and controls, respectively, p < 0.001) were larger in patients than controls, indicating impaired gallbladder emptying. Gallstone patients were divided into 19 "contractors" and 17 "hypocontractors" (residual gallbladder volume smaller or greater than mean +/- 2 SD of controls). Compared with the test meal alone, the addition of cholestyramine induced a further decrease of residual volume in contractors (from 30.4 +/- 2.1% to 19.8 +/- 1.9%, p < 0.001), hypocontractors (from 69.3 +/- 3.9% to 56.7 +/- 7.4%, p < 0.05), and controls (from 21.6 +/- 2.8% to 5.0 +/- 1.0%, p < 0.0004). Two hours after test meal plus cholestyramine gallbladder volume was still markedly reduced in both patients and controls. Fasting gallbladder volume 24 h after test meal plus cholestyramine was decreased in patients and in controls. The ingestion of cholestyramine alone initiated gallbladder evacuation comparable to that of test meal in both contractors and hypocontractors.
Conclusions: A low dose of cholestyramine in combination with test meal induces a considerable decrement of gallbladder volume compared with test meal alone in gallstone patients. Cholestyramine alone causes a decrease of gallbladder volume which is comparable to that observed in response to test meal alone.