Hello Doctor, My Husband Have Been Suffering From Liver Abscess

Hello doctor, my husband have been suffering from liver abscess and the doctor handling him admitted him and treated him and he got better and was going for regular checks, but at a point he stopped giving drugs and the sickness came back. But he is using only flagyl for the treatment and the pain is still there. But he said it will stop with the drug, and said my husband should come back in 3 weeks. But the pain is not reducing and he also said this type can't be drained. Is there no other painkiller that i can tell the doctor to add to his drugs. Thanks, am Silver from Nigeria.