complete colonic duplication in children

background: complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. complete colonic duplication can occur in 15% of gastrointestinal duplication. we report two cases of complete colonic duplications, and their characteristics. case presentation: we present two patients with complete colonic duplication with different types and presentations. case 1: a 2- year old boy presented to the clinic with abdominal protrusion, difficulty to defecate, chronic constipation and mucosal prolaps covered bulging (rectocele) since he was 6 months old. the patient had palpable pelvic mass with doughy consistency. rectal exam confirmed perirectal mass with soft consistency. the patient underwent a surgical operation that had total tubular colorectal duplication with one blind end and was treated with simple fenestration of distal end, and was discharged without complication. after two years follow up, he had normal defecation and good weight gain. case 2: a 2 –day old infant was referred with imperforate anus and complete duplication of recto-sigmoid colon, diphallus, double bladder, and hypospadiasis. after clinical and paraclinical investigations, he underwent operations in several stages in different periods, and was discharged without complications. after four years follow up, he led a normal life.conclusion: the patients with complete duplication have to be examined carefully because of the high incidence of other systemic anomalies. treatment includes simple resection of distal common wall, fenestration, and repair other associated anomalies.