Postoperative problems including pathophysiology at follow up were investigated in Kock's continent ileostomy in patients with ulcerative colitis. The results obtained were as follows: Though postoperative complication was found in all 4 cases, it was improved in 3 of them by conservative or surgical treatment. Troublesome skin irritation, such as erosion or ulcer, was not found in any case. The patients empty the reservoir when it is convenient and intestinal discharge was 1 to 4 times per day and these results were proved from the studies of the pressure and capacity in the Kock's ileostomy. Various plasma amino acids in patients with Kock's ileostomy showed almost similar levels to those of the normal subjects. Bacteriological examination in the stool in Kock's ileostomy also revealed almost similar results to those of the normal subjects. From these results, we conclude that Kock's continent ileostomy should be more widely performed for the patients with ulcerative colitis when ileostomy is required.