My Husband Has An Obvious Protruding Hernia, Umbilical. He Has

My husband has an obvious protruding hernia, umbilical. He has not had it looked at previously. Tonight it is red, with minimal pain to the touch and looks larger than before. We are trying to determine if we should go to the ER tonight or wait to have it checked out tomorrow at a doctor visit, but are concerned if we are missing the strangulation part and the ER is inevitable. No fever, and merely has mentioned the change and uncomfortableness.