Abstract : We report a case of complete transmural migration through the colic wall, followed by spontaneous defecation, of a surgical sponge left behind in the abdominal cavity (gossypiboma) during a vaginal hysterectomy with oophorectomy. The process results from encapsulation of the surgical sponge with fistulization through the colic wall. No functional damage followed this defecation because either the fistula closed early, or the sponge remained temporarily entrapped in a colic fold. The diagnosis was based on echography and computed tomography.