The oily stool may be caused by acute gastroenteritis, ulcerative colitis and other pathologies. 1. Acute gastroenteritis: this kind of lesion can appear diarrhea, abdominal pain, abdominal distension and other phenomena, there can be mucus stools, defecation can be with oil and other phenomena, mostly due to bacterial infections, can be treated by taking levofloxacin. 2. Ulcerative colitis: this kind of lesion can appear mucus, pus and blood stool, abdominal pain, abdominal distension, urgency and heaviness (lower abdominal discomfort, want to relieve the stool, after the stool has a sense of incomplete defecation), change of bowel habit, so the stool can be with oily material, can be treated by the use of drugs, such as salazosulfapyridine. There are many reasons for oily stools, so it is recommended to consult the hospital in time, and the above medicines should be used under the advice of a doctor.