A stomach ache with constant diarrhea is a symptom of diarrhea. If the diarrhea is more severe, it can be treated with medication. Diarrhea may be related to diet, chronic gastritis, enteritis and other diseases. It is recommended that the patient go to the hospital in time to clarify the cause of the disease and treat the cause. 1. Diet: When eating unclean diet or eating foods that are easy to cause diarrhea, such as poisonous mushrooms, tung oil, puffer fish, fish gall, etc., it can lead to stomach pain and diarrhea. Montelukast, alkaline bismuth carbonate and other drugs can be used to stop diarrhea. 2. Chronic gastritis: it can manifest as epigastric discomfort, pain, belching, diarrhea and other symptoms. Commonly used drugs are esomeprazole, omeprazole, lansoprazole and so on. When the diarrhea is severe, you can also use antidiarrheal drugs such as montelukast. 3. Enteritis: it can be manifested as fever, nausea, vomiting, abdominal pain, diarrhea and other symptoms. Commonly used drugs are acetaminophen, montelukast, bifidobacteria and so on. It is recommended that patients go to the hospital in time to clarify the cause of the disease. If medication is needed, it is recommended to use it under the guidance of a doctor.