The reason for diarrhea during menstruation is that the estrogen and progesterone in the body drop during menstruation, which causes the symptoms of water and sodium retention in the body. Oedema may appear on the surface of the body, including swelling of the hands and face, as well as oedema of the abdominal wall and internal organs, and the abdomen may feel swollen and full, and the breasts may feel swollen and painful. In addition, during menstruation, if water and sodium retention also cause the patient to gain weight, so there is no need to be nervous about this situation. If severe diarrhea occurs, you can go to the hospital for a detailed examination to rule out other gastrointestinal diseases. In case of mild diarrhea, it is recommended to make soup with carp and Astragalus membranaceus to drink during menstruation, which can effectively reduce the symptoms of sodium retention.