There are many reasons for diarrhea within an hour after eating, such as gastrointestinal dysfunction, inflammatory bowel disease, irritable bowel syndrome, etc., which can be treated with medications such as bifidobacteria, salicylazosulfapyridine, etc.; and also can be relieved by soothing the mood. 1. Gastrointestinal dysfunction: it is often related to the individual’s bad habits, such as staying up late, smoking, drinking, etc. It is recommended to take oral intestinal probiotics. It is recommended to take oral intestinal probiotics, such as Bifidobacterium bifidum, Bacillus subtilis and so on. 2. Inflammatory bowel disease: stomach pain and diarrhea often occur after eating, accompanied by mucus and pus and blood; it is recommended to perform colonoscopy and other related tests to clarify the cause of the disease, and then medication, such as luzosulfapyridine. 3. Irritable Bowel Syndrome (IBS): stomach pain after meal or before defecation is common, diarrhea manifested by increased frequency of stools, but the amount of stools per bowel movement is small, and the number of bowel movements is more frequent, most of them are related to stress, need to relieve mood and release pressure. Dilution within an hour after eating, there are many other reasons, such as frequent occurrence of postprandial stomach pain and dilution need to be timely to the hospital, the line of relevant examinations, to clarify the cause of the disease, symptomatic treatment.