Permanent ileostomy is usually recommended in the cases of total proctolectomy for cancerous change on the distal rectum from ulcerative colitis or familial adenomatous polyposis, but fecal content through conventional ileostomy is usually liquid or semiliquid. Sometimes, it accompanies dehydration and some nutrient loss as complication. So, the author has devised namely, "antiperistaltic ileostomy" for formed stool evacuation. About 25cm length of the most dismal ileum was cut and this distal segment was reversed with intact mesentery and then antiperistaltic ileostomy was performed. The author has performed antiperistaltic ilestomy in 5 cases of familial adenomatous polyposis, or ulcerative colitis with a cancerous change in the low rectum for the past 5 years at the Department of Surgery in Pusan National University Hospital. The results obtained were as follows. 1) In theantiperistaltic ileostomy, the 24-hour ileostomy discharge was averagely 748 cc, in contrast to 1124 cc from conventional one. 2) In terms of weight, the 24-hour evacuated material from the conventional ileostomy weighed 810 gm on the average, but only 540 gm from the antiperistaltic ileostomy. 3) The 24-hour filtered liquid through a coffee filter of the 24-hour ileostomy discharge weighed averagely 514 gm in the conventional group, which was 63.5% of the prefiltered discharge, and weighed averagely 160 gm in the antiperistaltic group, which was 29.6% of the 24-hour discharge. In conclusion, the antiperistaltic ileostomy is claimed to create the effect of a reservoir by producing intestinal stasis in the segment, forming bacterial proliferation. The antiperistaltic ileostomy as a terminal segment is effective in reducing the daily amount of stool and facilitates stoma care owing to diminished liquid component in the ileostomy discharge.