Girls sitting on the toilet stomach pain is most likely to be caused by menstruation and other factors, generally do not need special treatment; may also be caused by acute gastroenteritis, ulcerative colitis and other diseases, according to different diseases need to be treated accordingly. 1. Menstruation: During menstruation, because of the congestion of blood in the pelvis, girls will have the symptom of rectal pressure when going to the toilet, thus producing the feeling of sitting on the toilet with stomach pain. You can pay attention to keep warm during menstruation, do not need to use medication, if the pain is unbearable, you can take ibuprofen for pain. 2. Disease factors: acute gastroenteritis can have abdominal pain, diarrhea, combined with bacterial infections can use ciprofloxacin and other drugs anti-infective treatment, accompanied by severe diarrhea can be used to stop the diarrhea of loperamide; ulcerative colitis can have abdominal pain, diarrhea, mucus and blood stools of the symptom, you can use the willow nitrogen sulfonyl pyridine, oscarazidin, and other medications. Girls sitting on the toilet stomach pain, it is recommended to exclude physiological factors after timely medical treatment, under the guidance of the doctor for medication and treatment.