Foamy stool refers to the presence of foam in the feces, which is mainly considered to be related to dyspepsia, lactose intolerance and enteritis. 1. Dyspepsia: dyspepsia can be caused by gastrointestinal dyskinesia, Helicobacter pylori infection, and decreased diastolic function of the stomach to tolerate food. Some people with dyspepsia may have foam in the feces, which may be accompanied by postprandial fullness, burning sensation in the upper and middle abdomen, diarrhea and constipation. 2. Lactose intolerance: mainly caused by the lack of lactase enzyme that digests lactose, typical symptoms of patients include abdominal distension, hyperactive bowel sounds, diarrhea, nausea and vomiting, etc. Foam in the stool can be seen during defecation. Foam can be seen in the feces during defecation, and it is easy to be accompanied by sour odor. 3. Enteritis: Some patients with enteritis may also have foam in feces due to intestinal dysfunction. Enteritis is related to pathogenic microbial infection, abnormal immune mechanism, intestinal ischemia, etc. Patients are prone to abdominal pain, diarrhea, nausea and vomiting, fever and other symptoms. When there is foam in the feces, you should consult a doctor for examination in order to clarify the disease and then follow the doctor’s instructions for treatment. Recently, attention should be paid to the rationality of diet, avoiding the intake of cold, spicy and stimulating food.