5 months baby belly button red red may be related to friction injury, umbilical cord infection and so on. 1. friction injury: may be the baby’s diaper is too tight or not organized, the baby turned over when the navel area is subjected to repeated friction, resulting in the emergence of 5-month-old baby navel red. 2. Umbilicitis: may be the baby’s diaper is not breathable, dust or urine and other substances into the umbilicus, usually cleaning is not in place, caused by the umbilical cord infection umbilicitis, can be manifested as the baby’s navel red, may also be accompanied by secretion of the situation. 5 months baby navel red red can also be seen in other causes, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for relevant examinations, in the doctor’s help to clarify the cause, and targeted treatment or treatment.