What Causes Stomach Ache After Removal Of Sessile Polyps?

I had a colonoscopy yesterday afternoon. they removed 2 sessile polyps. Last night I hardly went to the loo for a wee, today i have hardly gone. I have stomach ache in the top half of my tummy. It doesnt feel like trapped gas.
I rang the hospital unit for advice, but they do not offer after care, they said ring my GP but they are closed. Is this normal