A small bag growing on the edge of the belly button may be caused by lipoma, folliculitis and other reasons. 1. Lipoma: Lipoma may be related to heredity, chronic inflammation and other factors, can occur in any part of the human body with adipose tissue, manifested as one or more lumps under the skin, generally small size, soft texture, gently pushed with the hand can be slightly mobile. 2. Folliculitis: when the navel edge of the skin is damaged, bacteria can easily enter the hair follicles, thus triggering folliculitis, manifested as red papules on the surface of the skin, pustular herpes, may be accompanied by pain or tenderness. A small bag on the edge of the navel may also have other causes, it is recommended to go to the hospital in time to improve the examination, clear cause to give targeted treatment.