Endometriosis is defined as a condition in which endometrial like cells appear and flourish in areas outside the uterine cavity. It is known that 3-37% of patients with pelvic localisation of endometriosis the digestive tract is engaged. Intestinal foci of endometriosis are usually situated on the external side of a bowel. Endometriosis localizated in mucous membrane is very rare. The most common symptoms are abdominal and pelvic pains, painful menstruation, dyspareunia. In our report we examine the case of a 44 years old female who was operated because of a bleeding sigma tumor. In histopathological examination – endometriosis.