Abdominal pain and diarrhea after chemotherapy for breast cancer is mostly considered to be caused by side effects of drugs, which is mild and needs no treatment, while serious cases need drug treatment. The drugs used in the process of breast cancer chemotherapy have toxic side effects, which will cause stimulation and damage to the mucous membrane of gastrointestinal tract, resulting in abdominal pain and diarrhea, etc. If the situation is not serious, no special treatment is needed. If the situation of diarrhea and abdominal pain is not serious, no special treatment is needed to maintain a light diet, easy to digest, and a week’s time can be gradually relieved and improved. Serious patients need medication, diarrhea requires the use of loperamide hydrochloride capsules, montelukast and other antidiarrheal drugs; abdominal pain needs to be targeted according to the cause of the pain, such as bacterial infections caused by the need to take norfloxacin, piperic acid and other antibiotics; spasm caused by the need to take antispasmodic drugs, such as belladonna. Drugs need to be taken under the guidance of a professional doctor according to the actual situation of the patient, do not take without authorization.