Frequent pain in the small abdomen: First, it is considered to be caused by gastrointestinal tract disorder or frequent gastrointestinal spasms. Second, it may be bladder and urinary tract diseases, such as cystitis and urinary tract infection can also cause pain in the small abdomen. But this pain is usually accompanied by frequent, urgent, painful urination, and even blood in the urine. Third, it may be a gynecological disease, such as pelvic inflammatory disease, vaginitis, vaginal erosion or cervical cancer may all cause pain in the small abdomen. Among them, if it is pelvic inflammatory disease, in addition to pain in the small abdomen may also cause pain in both lower abdomen. In addition, gynecological aspects, such as abdominal pain after delayed menstruation, may be caused by a preterm abortion after pregnancy, which is usually accompanied by vaginal bleeding. Fourthly, in men, it may be caused by prostatitis, which is usually a painful discomfort in the small abdomen near the pubic symphysis.