What causes anal spasmodic pain?

Aug 24, 2022 Source: Cainiu Health
Disease description:

On the third day of my sister's menstrual period, she experienced severe episodic pain in the anus for the first time, making it impossible to sit. She also has some bloating and cramping pain in the uterus. What could be the cause of the anal cramping pain?

Doctor's answer (1)
Dr. Zhao Haiming
Anal spasms are generally caused by spasm of the sphincter muscle, which can occur during acute episodes. Anal fissures and perianal abscesses can also lead to anal spasms, as can anal fistulas. Pus secreted during an anal fistula may irritate the anus, triggering spasms and resulting in pulsating pain. Pulsating anal pain is associated with conditions such as colitis, pelvic inflammatory disease, proctitis, gynecological disorders in women, and endometriosis.