Chief among them: Is anal sex poop a real thing? Ready for it? Yep, it might happen. But before you freak out, rest assured that there are things you can do make it less of a, well, messy affair It's also worth getting into a bit of an anatomy lesson: The colon processes waste, then sends it through the rectum where it stays temporarily , then the anus where it leaves the body.

Sign up for our newsletters Subscribe. Q: Background: I, a year-old male, enjoy receptive fisting. I've also had constipation problems all my life.

Having anal sex is like having large hard stools, only in reverse. It also lasts longer than a bowel movement, and may eventually result in greater carnage: enlarged internal hemorrhoids, anal fissures, ulcers, fistulas, nerve damage, rectocele, the weakness of anal sphincters, chronic pain, fecal incontinence, and, of course, chronic constipation. Anal sex causes constipation for the exact same reasons that large stools cause it — the diameter of even a small erect penis is as large or larger than the maximum aperture of the anal canal.