The sudden appearance of cramp-like pain in the anal area is mainly caused by a variety of perianal diseases, including the following: a. Painful symptoms caused by hemorrhoids, especially inflammatory external hemorrhoids and thrombosed external hemorrhoids, these lesions can form thrombi or venous blood clots around the anus and located under the skin, the main reason for this symptom is the occurrence of varicose veins around the anus. The painful symptoms caused by anal sinusitis, due to the special location of the anal sinus is easy to bacterial infection and hyperplasia and inflammation, thus pulling the perianal skin causes cramp-like pain. Pain caused by damage to the end of the rectum, including long-term poor diet, drinking a lot of alcohol or eating too much irritating food, etc., resulting in painful symptoms due to irritation of the rectal mucosa.