In the case of a rectovaginal fistula, the connection is between a woman's rectum and vagina. The opening allows stool and gas to leak from the bowel into the vagina. An ultrasound uses sound waves to create a picture from inside The surgeon will also fix the anal sphincter muscles if they're damaged. Here's what you need to know about anal sex poop, and what to do if it image. Getty Images. If you're gearing up to have anal sex for the first.