How can a doctor pull fluid out from behind a child's ear drum?

Rarely ever done: There is an uncommon but very valid procedure where a physician can draw fluid from behind the ear drum with a specialized needle. The canal is cleaned, made sterile and the ear drum is anesthetized or the kid put to sleep. The ear drum is pierced by the needle & material is drawn into a device with suction. This is usually done for research but some promote it for recurrent infections.