After the previous stage of diarrhea, you feel a slight pain in the left upper abdomen, which may be caused by chronic gastroenteritis, gastrointestinal tract dysfunction, inflammatory bowel disease and other disease factors; you need to be under the guidance of the doctor to carry out targeted treatment, such as medication, surgery and so on. 1. Chronic gastroenteritis: with bacterial infection can be treated with antibiotics, such as ciprofloxacin; with severe abdominal pain can be used to relieve pain; can also consider the use of lansoprazole, thioglycollate and other drugs. 2. Gastrointestinal dysfunction: After a gastrointestinal infection, gastrointestinal dysfunction may occur, which may be manifested as abdominal pain, diarrhea or nausea and vomiting. Accompanied by severe abdominal pain can be pain relief treatment, but also follow the doctor’s instructions to use bifidobacteria and other drugs to adjust the gastrointestinal micro-ecology, accompanied by anxiety, depression can be appropriate to give antidepressant drugs, such as fluoxetine, paroxetine and so on. 3. Inflammatory bowel disease: need to use Liuzosulfapyridine, azathioprine and other drugs under the guidance of a doctor, with hypoproteinemia patients recommended to supplement albumin, with intestinal perforation, hemorrhage and other cases to consider surgical treatment. Appearance of the previous stage of diarrhea well after feeling a slight pain in the left upper abdomen is recommended to go to the hospital, ask the doctor to make a comprehensive judgment, give treatment measures.