if the pain only started yesterday, the chances are that you have eaten something that has irritated a removal wound, this could be a sharp piece of hard food or something, even a crispy coating or sharp piece of toast could scratch an inflamed empty tummy on its way through. be nice to your tum and give it softer foods for a day or two and it should be ok.
I had a 4 cm polip removed a while back, yes 4cm! the biggest the surgeon had ever seen! the removal is painless as there are no nerve endings in the lining of the colon......, what made me feel ill was the drugs they gave before to empty/clense me the cramps made my tummy muscles hurt for a few days as the muscles had worked harder than they ever had! the drugs they gave during the procedure relaxed me but did not put me out cold, i was fascinated to watch the camera going through me on a screen beside me, even watched them snip off the polip and tattoo the site! I never dreamed i'd ever have a tattoo especially up my bum!
if the pain has been present from a few hours after the op it could be possible for internal bruising if the surgeon was rough and poked the scope/instruments against other organs/areas outside the colon....., but as the lining is delecate they tend to not push the sides too much in case they burst it.

hope you are feeling better soon. good luck with the path results x