Diarrhea and stomach pain may be associated with indigestion, intestinal inflammation, irritable bowel syndrome, and intestinal tumors. 1. Indigestion: Eating cold, spicy and stimulating, greasy and indigestible food, such as ice cream, spicy hot, etc., causes indigestion and diarrhea and abdominal pain. 2. Intestinal inflammation. (1) Acute gastroenteritis: bacterial infection caused by unclean diet, etc. Inflammatory stimulation leads to spasm of gastrointestinal tract and diarrhea and abdominal pain. (2) Crohn’s disease: the intestinal tract for a long time in the inflammatory period, resulting in patients with abdominal pain, abdominal distension, diarrhea, loss of appetite and other phenomena. (3) Ulcerative colitis: inflammatory changes in the mucosa of the colon, such as ulcers and erosions, lead to the secretion of large amounts of fluid from the intestinal mucosa, causing diarrhea and abdominal pain. 3. Irritable bowel syndrome: due to vegetative nerve disorder or lactose intolerance, dysbiosis, etc., it affects the intestinal digestion and absorption function, causing diarrhea and abdominal pain. 4. Intestinal tumor: Tumor ulceration or infection can cause diarrhea, abdominal pain, change of stool properties, blood in stool and other phenomena. There are many causes of diarrhea and abdominal pain, such as intestinal tuberculosis, etc. It is recommended to consult a doctor immediately to make a clear diagnosis, and actively treat under the guidance of the doctor.