My husband has small hole between buttocks. pus is coming out of it since 10 days and this is the first time. please suggest suggest some tablets.

An infected cyst?: A pilonidal sinus is a small hole, that may lead to a tiny tunnel, in the skin. It is usually at the cleft of the buttocks where they separate at the top. Showering each day helps keep the area clean, but there is nothing else to do for it unless the pilonidal sinus becomes infected. Then, it is treated with antibiotics and sometimes needs surgery to remove a cyst that has formed under the hole.