Colonic atresia is the least common form of intestinal atresia. Colonic atresia, like jejunoileal atresia, mostly occurs as a result of an intrauterine vascular accident. According to Sutton's classification, type 1 colonic atresia exibits external continuity with an intraluminal diaphragm(colonic web) which may be imperforate or perforate. Authors experienced a case of colonic web associated with imperforate anus. The patient was treated under the impression of the high type imperforate anus. Posterior sagittal anorectoplasty at the age of 9 months revealed normal anorectal canal. At the age of 12 months, colostomy was repaired. Thereafter abdominal distension was developed. Barium enema noted a membranous obstruction of the colon on the level of the rectosigmoid junction. After exicision of the colonic web, the patient was discharged with no problem.