1. Bile salt metabolism has been studied in seven patients with ileostomy following total proctocolectomy; three of these patients also had various degrees of ileal resection. 2. The half-life of the cholic acid pool was shortened in the patients with ileal resection. 3. Rates of bile acid synthesis were raised in two of the three patients with ileal resection. In the third, the rate was normal. 4. Four of the six patients had low bile acid concentrations in the duodenum after a fatty meal. 5. Deoxycholic acid could not be detected in the duodenum or ileal effluent of any of the patients.