Intraoperative discovery of complete colonic duplication with duplicated caeca, appendices, vaginal orifices, and anorectum in a dizygotic twin: a case report

Abstract Background Complete colonic duplication is an exceptionally rare congenital anomaly that, when it occurs, often falls within the caudal duplication spectrum alongside vaginal and anorectal malformations. We report a rare case of complete colonic, caecal, and appendiceal duplication combined with duplicated vaginal orifices and anorectal malformation in a female dizygotic twin, incidentally discovered during surgical repair. Case Presentation A female infant, one of dizygotic twins, presented at birth with stool passing through an abnormal perineal orifice, clinically diagnosed as anorectal malformation of the vestibular type. Due to poor general condition in the neonatal period, primary surgical correction was deferred; the infant was managed conservatively with rectal saline irrigation from day nine of life, followed by right transverse colostomy at four months of age. At 7 months, during planned anorectoplasty under general anaesthesia, the surgical team incidentally identified two anal orifices and two vaginal orifices. Intraoperative extension of the procedure through a lateral abdominal incision revealed complete duplication of the colon, caecum, and appendix. No preoperative imaging had been performed; the entire duplication anomaly was thus an unexpected intraoperative discovery. The patient underwent anorectoplasty, vaginoplasty, and revision of the right transverse colostomy. Postoperatively she was managed with intravenous antibiotics, analgesia, and wound care, with satisfactory recovery. Her dizygotic male co-twin was clinically normal with no evidence of any congenital anomaly. Conclusion This case represents an exceptionally rare combination of complete colonic, caecal, and appendiceal duplication with concomitant duplicated vaginal orifices and anorectal malformation in a dizygotic twin. It underscores the importance of systematic intraoperative exploration in resource-limited settings, where complex duplication anomalies can masquerade as simple anorectal malformations until surgery reveals otherwise.