We report a case of acute colonic obstruction initially presumed to be seco
ndary to acute diverticulitis, necessitating emergent surgical intervention
. Pathologic examination failed to reveal evidence of inflammation, fibrosi
s or neoplasia. Marked hypertrophy of the sigmoid circular muscle layer was
documented and thought to be the etiology of the colonic obstruction. sigm
oid colon, muscle hypertrophy, barium enema.