A feeling of anal cramping is usually most common with lesions close to the anal area. Generally, if you have hemorrhoids, your bowels are blocked from passing through and you will experience a feeling of anal swelling. If there is a tumor in the rectum that causes narrowing of the intestinal cavity, the gas cannot pass, including the passage of stool, and the feeling of swelling cannot be reduced. These are the two most common causes. There is also a rare clinical condition called rectal prolapse, where the patient has a feeling of anal distention, and cannot finish the bowel movement, and still feels it afterwards. In this case, a barium enema should be done to clearly identify the problem. For hemorrhoids, you need to go to the anorectal department, and for rectal problems, you need to do a proctoscopy or colonoscopy to further clarify the cause of anal cramping.