The smell of feces in the buttocks may be caused by perianal abscess, hemorrhoids, anal fistula and other diseases, or it may be caused by poor hygiene habits. 1. Perianal abscess:Most of the perianal abscess is caused by anal crypt infection, patients will have pain in defecation, distension, pus from the anus outflow and other symptoms. Patients will appear abscess breakthrough outflow phenomenon, there will be a bad smell, so the patient will have buttocks with the smell of feces performance. 2. hemorrhoids: the etiology of hemorrhoids is not clear, considering that it is due to the theory of anal cushion downward movement, varicose vein theory and other factors. The patient’s main symptoms for blood, hemorrhoids prolapse, necrosis, hemorrhoids will lead to anal relaxation, feces will overflow out of the anus, so the patient will appear buttocks smell of feces symptoms. 3. anal fistula: anal fistula is mostly due to rectal perianal abscess, patients will have discharge, itching, fistula defecation, pain and other manifestations. Anal fistula will lead to fistula external mouth with fecal discharge and purulent secretion discharge, so patients will appear buttocks have the phenomenon of fecal odor. If it is because of bad living habits, do not pay attention to personal hygiene led to this kind of situation, need to pay attention to diligent bathing and dressing, remove body odor. When the patient has the symptom of ass smell, he should consult a doctor in time to find out the cause of the disease and follow the doctor’s instructions for treatment.