If your rectum is inflammed, a fistula may create between the rectum and your urinary
bladder. Other posible cause would be
infection with some bacteria which produce gas.
Light stool (if yellow) means lack of bile acids (which normally give brown color of the stool). The cause may be liver disease or stones in the biliary ducts. If the stool is pale (whitish), foamy and sticky, this means fats in stool due to their inappropriate absorption in small intestine, due to infection or inflammation.