Frothy stool refers to the appearance of foamy mucus when defecating. If this problem occurs, it may involve the following two major aspects: 1. It is suggested that it is related to functional lesions of the gastrointestinal tract. Patients may have indigestion, poor digestion, excessive food residues, which are fermented and produced by bacteria in the intestine, and they will have frothy stools mixed with foam. 2. It may be related to organic lesions of the intestine. Because of bacterial, viral infection or other inflammation of the intestinal tract, may lead to its accompanied by foamy stools. So if you encounter this situation, you should also ask the patient if there is bleeding, abdominal pain and changes in the number of stools. In conclusion, if the stool is often frothy, the patient is advised to go to the gastroenterology department for symptomatic examination and, if necessary, colonoscopy.