Volvulus of the ascending colon due to failure of zygosis: A case report and review of the literature.

•The ascending colon has been described as a retroperitoneal organ however it may occasionally have a long mesentery.•The process of peritoneal zygosis is incompletely understood and is subject to perturbation leading to many abnormalities.•The excessive mobility may predispose to volvulus of this intestinal segment.•There is often a long symptomatic prodrome before volvulus occurs during which the observant surgeon may intervene.•The mesentery has gained new relevance with respect to its role in the contemporary management of surgical diseases.