Most prolapsed hemorrhoids begin as an internal hemorrhoid in the lowest part of the rectum, just inside the anus. The hemorrhoids can then swell and descend through the anus, which is then referred to as a "prolapsed hemorrhoid." The blood vessels may shrink back up into the rectum, but others may become permanently prolapsed, meaning that they remain outside the anus permanently.
For some, prolapsed hemorrhoids can result in bloody stools. If severe, they may require surgery, especially if they are permanently prolapsed. For many hemorrhoid patients, dietary changes and alterations in bathroom habits can be very effective and surgery is not necessary.
Hemorrhoids are very common, with 75% of all people having one or more at some point in their life.