Diarrhea in bedridden elderly may be caused by intestinal flora imbalance, acute gastroenteritis, dyspepsia, ulcerative colitis, intestinal cancer and other reasons. 1. Intestinal flora imbalance: diet or medication can lead to intestinal flora imbalance, harmful bacteria multiply more, causing diarrhea in bedridden elderly. 2. Acute gastroenteritis: bedridden elderly people have weaker digestive ability, eating unhygienic food can cause acute gastroenteritis, resulting in diarrhea, abdominal pain, intestinal sounds and other symptoms. 3. Indigestion: bedridden elderly gastric peristalsis is slow, not fully digested food discharged into the intestine, can stimulate intestinal peristalsis, causing diarrhea and other symptoms. 4. Ulcerative colitis: it mainly manifests as diarrhea, mucus-pus-blood stool, abdominal pain and other symptoms. 5. Intestinal cancer: infiltration of local tissues by cancer cells can lead to diarrhea, abdominal distension, emaciation, anemia and other symptoms. There are many reasons leading to diarrhea in bed-ridden elderly people, so it is recommended to consult a doctor in time to find out the cause of the disease under the guidance of a professional doctor and follow the doctor’s instructions.