The causes of indigestion and residue in stool include dietary factors, intestinal infections and intestinal tumors. 1. Dietary factors: such as overeating, eating a lot of greasy or rich in crude fiber food, will increase the burden on the gastrointestinal tract, causing temporary indigestion, can not fully digest food, can appear indigestion, food residue. 2. Intestinal infection: Usually the intestinal peristalsis function of patients with enteritis is abnormal, either reduced or hyperactive, if the peristalsis function is reduced, it will cause indigestion and food residue in the stool. 3. Intestinal tumors: such as rectal cancer, colorectal cancer, colon adenoma and other intestinal tumors, destroying the normal intestinal tissues, which leads to intestinal peristalsis and makes the intestinal mucosa absorption ability are reduced, so there will be food residue in the stool. There are many other causes of indigestion and residue in the stool. Chronic pancreatitis patients with pancreatic exocrine insufficiency will also have the phenomenon of fat drops or undigested food in the stool. Attention should be paid to timely consultation, identify the cause of the disease, and follow the doctor’s instructions for further treatment or therapy.