SUMMARY Twenty patients with ileostomy were studied concerning the absorption of D-xylose, fat, L-phenylalanine, and vitamin B12. Ten patients had a conventional ileostomy, whereas 10 others were provided with an intraabdominal intestinal ileostomy reservoir resulting in faecal continence.No remarkable differences in the absorption of D-xylose, fat, or L-phenylalanine were found between the two groups of ileostomy patients. Most of the absorption values were within normal or borderline ranges. In the reservoir group the Schilling test gave subnormal values in six out of 10