My five month baby has an inch of protruding belly button. will that cause him any harm?

Umbilical hernia: Not a problem provided the protruding belly button can easily be pushed in when he is lying down. You can feel an "gap", with your finger, in the abdominal wall fascia deep to belly button. This should close in time, by age 2 - 3-years in caucasian children and up to 5-years in african or aa children. You can also tell if the gap is getting smaller with time. Need 2B reparired if it enlarges.