Dietary factors, constipation, gastrointestinal tract dysfunction, etc. are some of the causes of decreased stool volume. 1. Dietary factors: Reduced intake of food or consumption of food with less residue after digestion and absorption, such as rice and soy milk, can lead to a decrease in the amount of stool. 2. Constipation: Due to the decrease of dietary fiber intake or the decrease of water intake, intestinal obstruction, etc., the stools are dry and not easy to be discharged, which leads to a decrease in the number of bowel movements of the patients. 3. Gastrointestinal tract dysfunction: due to overeating, unclean diet, mental and psychological stimulation and other factors, resulting in increased burden on the gastrointestinal tract, gastrointestinal tract dysfunction, gastrointestinal peristalsis slows down, thus leading to a decrease in the number of bowel movements. If there is a decrease in the number of stools, it is recommended to go to the hospital in a timely manner to clarify the cause of the disease and follow the doctor’s instructions for treatment.