Baby stool with blood, may be due to anal fissure, small intestine mucous membrane damage caused. 1. Anal fissure: If the blood in the baby’s stool is attached to the surface of the stool, it is mostly due to anal fissure. In addition, the baby may be accompanied by crying, straining to defecate, dry stools and other phenomena, the anus may appear small fissures, manifested as a small amount of blood on the stool. 2. Damage to the mucosa of the small intestine: if the mucosa of the small intestine is damaged, the baby will also have blood in the stool. Usually occurs because the intestinal tolerance is poor, after eating mucosal damage, blood into the intestinal lumen and excreted with the stool, the baby will have blood in the stool. If your baby has blood in the stool, it is advisable to seek medical advice and make symptomatic interventions as prescribed by your doctor.