The most common causes of chronic diarrhea are intestinal infections, followed by intestinal tumors, other factors such as small intestine malabsorption and non-infectious inflammation, and some cases with unknown causes are as follows: 1, diarrhea caused by gastric diseases and regurgitation of intestinal contents or bile into the stomach. 2, diarrhea caused by various intestinal diseases, such as bacillary dysentery, clonorchiasis, ulcerative colitis, incomplete intestinal obstruction, tumors, dyspepsia, and dysbiosis. 3, diarrhea caused by endocrine disorders such as hyperthyroidism, diabetes, hypoadrenocorticism, etc. 4, functional diarrhea, such as emotional diarrhea, irritable bowel syndrome. 5, certain diarrhea drugs, antihypertensive drugs caused by the pharmacogenic diarrhea. 6, allergies to fish, shrimp, food poisoning and other diarrhea caused by.