The mouth of the fecal tract may refer to the anus, and if pus flows from the anus it may be caused by inflammatory bowel disease, bacillary dysentery, rectal polyps, intestinal tumors and other factors. 1. Inflammatory bowel disease: Crohn’s disease, ulcerative colitis and other inflammatory bowel disease, mainly due to immune dysregulation, high-fat diet, poor lifestyle, intestinal flora imbalance and other factors, may appear changes in bowel habits, may appear mucus pus blood stool. 2. Bacteriophageal dysentery: Decrease in human resistance caused by overeating, over-fatigue, chronic diseases and other factors can lead to intestinal bacterial infections, triggering bacillary dysentery, which can be characterized by mucus, pus and blood in the stool. 3. Rectal polyps: when rectal polyps occur, due to the stimulation of polyps in the intestinal tract, it can lead to mucus adherence in the discharged stools, and pus-like stools can occur. 4. Intestinal tumor: when colorectal cancer and other intestinal occupational diseases occur, due to the intestinal mucosal damage, intestinal bleeding and mucus secretion, pus-like stools can occur. When pus-like stools appear in the mouth of feces, one should consult doctor in time and take appropriate treatment under the guidance of specialized doctors, which will help to cure the disease as soon as possible.