Wounds and tears in the anus can arise after a period of firm stool or heavy diarrhea. This causes, especially during and right after passing, heavy pains. Because it has become so painful, defecation is postponed, causing the stool to become even firmer. Generally, the wounds heal on their own within a few weeks. If after six weeks a wound was still not healed, we speak of a chronic fissure which needs to be treated. The fissures are usually localized at the front or the back of the anus, where the circulation is insufficient. Because of heavy pains, the sphincter is tightened subconsciously causing the circulation to lessen even more. Treatment focusses on improving circulation in this area.
Constipation or firm stool can be prevented by a diet rich in fiber, sufficient fluid intake and exercise. Sometimes these measures are insufficient and laxatives are required.