Dyspareunia during menstruation may be caused by unclean diet, cold abdomen, indigestion and so on. 1. Unclean diet: If you often eat some unclean food or irritating cold food during menstruation, it may lead to increased gastrointestinal burden and cause diarrhea. 2. Cold abdomen: Since the body of a woman who is having a baby is weak, if she does not pay attention to keep warm and her abdomen gets cold, it may cause diarrhea in the woman who is having a baby. 3. Indigestion: If a woman consumes too much nutrition during her menstrual period, it will increase the burden on her intestines and make it difficult for her to digest and absorb the food adequately, which may lead to diarrhea. Women who have diarrhea during menstruation should pay attention to keep their abdomen warm and eat a light diet in their normal life. When the symptoms are serious, they should go to the regular hospital in time and be treated under the guidance of a professional doctor.