5-year-old baby underpants always have poop may be due to improper personal hygiene, indigestion, diarrhea and other reasons, should be promptly ruled out physiological factors to determine the real cause of the disease. 1. Improper personal hygiene: due to the age of the child, may be at the end of defecation, in the process of wiping the buttocks, wipe not thoroughly, so that the buttocks still have a small amount of feces, sticky in the underpants, resulting in underpants always have poop situation. 2. Indigestion: Due to young age, irregular diet, gastrointestinal dyskinesia, decreased tolerance of food in the stomach, and bacterial infections, indigestion occurs in the epigastric region, manifesting symptoms such as diarrhea and vomiting. 3. Diarrhea: due to bacterial and viral infections, eating food that is not cooked, etc., so that the intestinal tract is infected, causing diarrhea, so that the number of stools increases, the onset of the disease is acute, and may be accompanied by abdominal pain, so the baby’s underpants always have a poop may be caused by diarrhea. It is recommended that in daily life, parents to improve the child’s autonomy, pay attention to dietary health and safety, such as accompanied by other symptoms of physical discomfort, should be timely to the hospital for examination.