Perianal abscess defecation with pus may be caused by abscess rupture, defecation with pus may also be caused by ulcerative colitis, Crohn’s disease, dysentery. 1. abscess rupture: when the patient has a perianal abscess, acute suppurative infection occurs in the soft tissues around the rectum and anal canal or in the surrounding interstitial space, after the rupture, resulting in the emergence of pus in the patient’s bowel movements. 2. Ulcerative colitis: under the effect of environmental, genetic, micro-ecological factors, intestinal immunity imbalance, resulting in damage to the intestinal mucosal barrier, thus causing defecation with pus, accompanied by abdominal pain, diarrhea and other symptoms. 3. Crohn’s disease: when patients are affected by infection, immunity, genetics and other factors, there will be a situation of pus in the stool, accompanied by abdominal pain, diarrhea, fever and other symptoms. 4. Dysentery: Perianal abscess with pus in the bowel movement may be caused by dysentery, mainly associated with improper diet and other factors, the patient also appeared bad breath, abdominal pain and other symptoms. It is recommended that patients go to the regular hospital in time, under the guidance of the doctor, the relevant examination, a clear diagnosis, according to the patient’s specific condition, to take active and reasonable treatment, to avoid adverse effects on the body, triggering the emergence of other diseases.