An anal fissure is a tear or cut that extends into the anal canal. Constipation - large, hard feces (stools) are more likely to result in lesions in the anal area during a bowel movement than Anal sex - can in rare instances cause anal fissures. If you like anal sex, there's no reason to be ashamed of it. Having anal sex if Generally, while the specter of potential poop is terrifying, it does not happen. I mean, you won't just Photo Credit: Getty. Anna Breslaw Writer. Proctitis means inflammation of the rectal lining. Stool passes through the rectum on its way out of the body. Sexually transmitted infections, spread particularly by people who engage in anal intercourse, can result in.