That's why it's a good idea to pay attention and not let any odd scents go on ignored. They originate in a tiny anal gland, which enlarges to create a site of infection under the skin. If your motions stools, shit, poo are black like tar see your GP right away as you may be bleeding from the erosion or ulcer. Rectal cancer is rare in men under 40 years but any changes in bowel habit or internal feeling should be check by your doctor.
Search Harvard Health Publishing
It can be very difficult for those affected by rectal prolapse to clean and stay clean. One way to tell is to look at the stool.