Mine was quite painful and I needed narcotic pain relief for 2 weeks post op. Once it healed it was awesome though and has been a great benefit since then. I will suggest making sure the surgeon did not put the bumper on too tight. It can add a lot of unnecessary pain and discomfort. This was part of my issue post op. I learned from talking to other people with g-tubes that this happens a lot. The surgeons have you flat on your back, so when they put the bumper flush with your skin it seems fine then, but when you sit up and your stomach pushes forward it's way too tight. You can loosen it yourself to a comfortable position.
I would also do away with those split sponges they send you home wearing. All they do is hold wetness against the skin causing skin irritation (like diaper rash). Keep it clean and dry. Hydrogen peroxide can impede healing early on (skin breakdown), I prefer non-alcoholic witch hazel to gently clean the stoma. Air dry. I do like the cloth reusable tube pads, they wick moisture rather than holding it to the skin like the split sponges, but not everyone is a fan of them. Try things and see what works for you. Another thing is make sure you rotate the tube periodically, and avoid taping it in the same place every time, as that tends to cause more granulation tissue- a wet pink/red tissue that you might see growing around the tube. Do not be alarmed, while annoying, it's common and can be prevented with better stoma care, and treated/managed with hydrocortizone cream, or a product called granulotion.
If you are on facebook I'd advise joining the group "Adult tube feeding". There are veteran "tubies" on there who can help you troubleshoot any issue and offer tips and great advice.