sigmoidocele sigmoidocele sigmoidocele (also known as pouch of douglas descent) refers to a condition where the sigmoid colon descends (prolapses) into the lower pelvic cavity. this can obstruct the rectum and cause symptoms of obstructed defecation. sigmoidocelespecialtygastroenterology pathophysiology the phenomenon is caused by a weak section of fascial supports of the vagina (the uterosacral cardinal ligament complex and rectal vaginal septum), which allows a section of peritoneum containing the sigmoid colon to prolapse out of normal position and fall between the rectum and the vagina. diagnosis it is not possible to differentiate between a rectocele and a sigmoidocele on vaginal examination. defecating proctography will demonstrate a sigmoidocele during straining. epidemiology sigmoidocele normally occurs in females, and is uncommon.