1 week old baby’s belly button protrudes for the following reasons: a. Due to the normal abdominal wall tension, muscle tone is poor, feeding or abdominal distension will lead to the baby’s belly button slightly protruding condition, but when you touch the belly button with your hand does not feel the state of the intestinal tube, is not an umbilical hernia, but the belly button protrudes due to high intra-abdominal pressure, do not need to worry, as the child grows, the abdominal muscle tone is getting better then this phenomenon will disappear. phenomenon will disappear. The umbilical hernia is caused by the protrusion of the navel, and when you feel the protruding part of the navel with your hand, you can feel the intestinal tube and intestinal contents, so you need to go to the hospital for examination to see if surgery is needed.