Background: Colestimide is a newly developed bile acid‐binding resin in Japan, but its bile acid‐binding properties have not been studied.

Methods: The absorption of unconjugated bile acids (5 mmol/L) in the ligated rat jejunum was compared in the presence and absence of colestimide. Furthermore, bile acid adsorption by colestimide was also studied in vitro.

Results: All bile acids were efficiently absorbed in the jejunum and the cumulative absorption during 120 min was 29–63%. The absorption of chenodeoxycholate, lithocholate, deoxycholate and ursodeoxycholate was dose‐dependently inhibited by 2.5 and 5 mg colestimide, whereas the absorption of cholate was not inhibited, even in the presence of 5 mg colestimide. Adsorption of bile acids by colestimide in vitro was approximately 60% for chenodeoxycholate, lithocholate, deoxycholate and ursodeoxycholate, whereas the adsorption of cholate was low (16%).

Conclusions: Jejunal absorption of ursodeoxycholate was inhibited by colestimide to a similar extent as other dihydroxy bile acids, whereas that of cholate was not inhibited under the same conditions.