One year old baby stool irregularity is considered to be caused by physiological factors, may also be indigestion, acute gastroenteritis and other factors triggered. 1. Physiological factors, due to the one-year-old baby body is not fully developed, digestion and absorption capacity is weak, may appear one-year-old baby stool irregularity symptoms. 2. indigestion, if usually eat too much at once, indigestion, may lead to abdominal pain and diarrhea and other symptoms, so it will lead to the baby’s stool irregularity. 3. Acute gastroenteritis, clinically acute gastroenteritis after the invasion of bacteria and viruses or other pathogens, may lead to one-year-old baby stool irregularity. One year old baby stool irregularity may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, to give targeted treatment or treatment.