Suggest Diet And Post Surgical Care After Disceotomy Surgery

My son underwent a discectomy 3 months ago of the L5-S1. Please advice me as to what diet he can have to recover well. He has water retention due to the dichlopheneac that he has to take for the pain.
He also has to take a 3 week paracetamol course with a rest period of 3 weeks for the next 3 months. Please advice on diet and post surgical care. Many thanks.