Constipation in one-year-old children may be caused by drinking less water, improper diet structure, indigestion and other reasons. 1. Drinking less water: the reason for constipation is that when food enters the stomach and intestines, nutrients are gradually digested, while the absorption of water is dominated by the colon. If you don’t drink enough water, the excreta will enter the colon and absorb the excess water, leading to dry stools. 2. Improper dietary structure: Eating food that is too fine, that is, eating food that contains a low content of plant fiber can also lead to constipation. 3. Indigestion: the gastrointestinal digestive ability decreases, unable to digest and absorb food in a timely manner, food in the intestinal tract stagnation, dry stools, stool frequency decreases. When a one-year-old child is constipated and physiological factors such as low water intake are ruled out, he or she should go to the hospital as soon as possible to avoid the development of the disease.