Most of the diarrhea after chemotherapy for stomach cancer is normal, which is a common side effect of chemotherapy drugs. The drugs used in chemotherapy for stomach cancer have certain toxic side effects, which will cause stimulation and damage to the gastrointestinal tract of human body, thus causing diarrhea, vomiting and loss of appetite, which are normal reactions to chemotherapy. If the diarrhea is not very serious, there is no need for special treatment, and the condition will recover naturally after the chemotherapy is finished. If the situation is more serious, it is necessary to use antidiarrheal drugs such as loperamide and montelukast under the guidance of doctor or clinical pharmacist, and at the same time, glucose and saline can be injected intravenously in order to avoid dehydration, and chemotherapy can be suspended when necessary, and then continue the subsequent treatment after the situation has improved and recovered. Gastric cancer chemotherapy will be accompanied by certain adverse reactions, which need to be well taken care of and monitored, and followed the doctor’s instruction to adjust and improve.