Menstruation did not appear small stomach pain causes very much, examples are as follows: 1, more common is due to changes in hormone levels in some women’s bodies, in the pre-menstrual period will appear small stomach pain, pay attention to observe the late period will occur, there is also due to pregnancy and the future of menstruation and small stomach pain; 2, due to the woman appeared in the acute pelvic inflammation led to pelvic congestion, edema, or even pelvic Fluid accumulation, there will be pain in the stomach, but often accompanied by abnormal leukorrhea, gynecological examination or ultrasonography, can be further clarified; 3, due to acute gastroenteritis caused by pain in the stomach, usually nausea, vomiting, abdominal distension and other gastrointestinal symptoms; 4, due to urinary tract diseases, such as urinary tract infections, stones, and so on, there may be pain.