Torsion or volvulus of the right side of the colon is one of the rare causes of intestinal obstruction. Though much less often mentioned in the literature than sigmoid volvulus, and less often encountered in surgery, it is probably of greater importance in the usual surgical clinic for adults, since twists and obstructions of the sigmoid are almost invariably associated with congenital megacolon (Hirschsprung's disease), a condition which in many instances becomes fatal or is successfully treated in infancy and childhood. Indeed, in this clinic, the count stands three cases to none in favor of the ascending colon. The pathology of this accident rests on certain well studied congenital maldevelopments, plus a functional disturbance, in which a most interesting and little understood factor is the power of rapid gas formation possessed by the intestinal canal. As a sine qua non for the development of a twist of the right colon,