What would cause colon to not complete bowel movement - retain some and cause bad odor despite clean tpaper? fix?

Doctor to evaluate: There are several reasons why poop would end up stuck in the rectum, so a primary care doctor or a G.I. Specialist should evaluate. Causes include constipation (slow transit of stool through the intestine), medications that slow the bowel, nerve disorders that slow the bowel, tumors blocking flow of the stool, etc... A patient can use laxatives to keep the rectum clear, awaiting his appointment.