The pain in the small stomach and anus is caused by the following conditions: 1. The pain of cramping is usually due to the presence of intestinal spasm, often accompanied by intestinal tinnitus and diarrhea, which is commonly caused by unclean diet, resulting in intestinal contents that are not tolerated, and then cramp-like pain. 2. The actual pain can be a result of the urinary system ultrasound and also anoscopy to rule out the possibility of submucosal abscesses of the rectum or anal abscesses. 3. To sum up, if the condition is serious, go to the hospital promptly for the right medicine.