Relationship between Faecal Bile Acids, Absorption of Fat and Vitamin B12, and Serum Lipids in Patients with Ileal Resections

Abstract. Faecal bile salt, neutral steroid and fat excretion, vitamin B₁₂ absorption, and jejunal lipids, bile acids and cholesterol during fat digestion, serum cholesterol and cholesterol synthesis were measured in 3 patients with incomplete (IIR) and 9 patients with complete (CIR) resection of the terminal ileum. These parameters were virtually normal in IIR and in one case with CIR while in other cases they were frequently abnormal, bile salt excretion being increased up to 12-fold. The finding that faecal bile salts correlated positively with faecal fat and cholesterol synthesis, and negatively with jejunal constituents and serum cholesterol, supports the previously unproved concept that augmented elimination of cholesterol into faeces as bile acids proportionately depletes serum cholesterol despite increased cholesterol synthesis, proportionately decreases jejunal bile salts despite markedly augmented bile acid production and proportionately impairs micellar solubilization of lipids during fat absorption, leading to steatorrhoea. Furthermore, faecal bile salts showed a positive correlation with faecal water and a negative one with the Schilling test values. Faecal bile salts are suggested to be a sensitive indicator of ileal dysfunction.