You should not drink alcohol for at least 24 hours after a general anaesthetic or sedation. Some Royal College of Anaesthetists guidance also says to avoid alcohol for 24 hours after an epidural or spinal, and to avoid alcohol while you are recovering and your judgment may still be affected. If you had a major operation, it may take longer for you to feel fully back to normal. Verify the exact plan with your surgical or anesthesia team in case they want something different for you.