Depends how bad
These days it is usually done with laparoscpes (cameras) and you end up with a small hole in your belly-button and 2 smaller hole on your stomach.
You usually have pain requiring narcotics for 3 to 7 days and then are sore for another week. Most surgeons ask that you not do strenuous activity for 3 to 4 weeks after. Big or trapped hernias may require a larger cut on your belly.