The diarrhea and bloody water are related to acute enteritis, ulcerative colitis, intussusception and bacterial dysentery, etc. 1, The main site of ulcerative colitis is in the colon, and in serious cases, the ulcerated surface of the colonic mucosa may even appear to be oozing blood, which will not only cause diarrhea, but also blood in the feces. 3. If the intestinal stack is not treated in a timely manner, it will lead to increased venous reflux disorders in the intestinal wall, and once the blood supply to the intestinal wall is insufficient, necrosis of the intestinal wall may even occur. 4, dysentery bacillus is a harmful bacteria, will cause aggression to the intestinal mucosa, and even lead to intestinal mucosa necrosis, detachment, so in serious condition, patients will not only appear diarrhea symptoms, but also appear mucus pus blood stool.