The external anal sphincter is a thick, red voluntary muscle. It is wrapped around the internal anal sphincter muscle. It is the one you squeeze when you feel the urge to go to the bathroom but are not near one. Since it is voluntary muscle, like the muscles in your arms and legs, you can control it. Anal stenosis means that the anal opening is too small, or that it does not relax or open properly.
Scar tissue can cause anal stenosis.
This may need to be treated with surgery that brings a flap of skin down to enlarge the anal opening. In some people, the internal anal sphincter does not relax as it should. This makes the anal opening too small. Top of page. For best results, screen resolution should be 800x600 at 16 million colors.