[Undetermined colitis].

Indeterminate colitis combines features of chronic ulcerative colitis and Crohn's colitis and contemplates a dilemma for the patient and surgeon contemplating ileal pouch anal anastomosis. Some series have reported a high incidence of failure of pouch procedures in patients with indeterminate colitis. A series reported by the authors in 1989 reported a failure rate on approximately 9% with indeterminate colitis. In updating this series with additional patients operated on since that time, the incidence in our series approaches 20%. We feel that an 80% success rate, however, justifies performing the ileal pouch anal procedure in carefully selected patients with indeterminate colitis, knowing that the failure rate may be somewhat higher than in patients with type ordainer chronic ulcerative colitis.