Patients who have frothy stools with diarrhea can be considered to be caused by the following reasons: First, it can be considered to be caused by cold in the abdomen. Second, it may be caused by indigestion, such as the recent consumption of too much food containing starch or sugar, there will be diarrhea with froth in the stool, this is because starch or sugar food will lead to the fermentation of the original food in the human intestinal cavity, then there will be a dark brown watery stool with foam. Third, it can be considered to be caused by viral infection. Fourthly, it can be considered as a result of chronic colitis. All of the above causes can cause patients to have frothy stools when they have diarrhea, and patients with serious conditions are advised to go to the relevant departments of the hospital to have the cause examined in a timely manner.