My baby is having small hole in crease of buttock just above the anus is that normal ?

A. A pilonidal sinus is a sinus tract which commonly contains hairs. It occurs under your skin between your buttocks (the natal cleft) a short distance above your back passage (anus). The sinus tract goes in a vertical direction between your buttocks. Rarely, a pilonidal sinus occurs in other sites of your body.A sacral dimple is a small, usually shallow indentation in the small of the back, just above or within the crease of the buttocks. About 3 to 8 percent of the population has a sacral dimple. A very small percentage of people with a sacral dimple can have spinal abnormalities. consult your pediatrician once.