The painful anal cramps may be due to the following reasons: 1. The anal area may be in spasm due to inflammatory stimulation of the anus, making it narrow and difficult to pass stool or causing pain in the anal area. 2. The painful cramps may be due to anal fissures, which are usually caused by dry stools and rupture of the skin of the anal canal during forceful defecation. The pain can be caused by a 90-degree angle between the anal canal and the rectum, which increases the pressure on the back wall of the anal canal when defecating, so when the anal fissure occurs, it can cause the person to feel pain like a cramp in the anus. 4.