Talk to Gastroenterologist on Stomach Ache

I recently had wisdom tooth removal for which the dentist had given antibiotic for three days and synflex pain killer. Since I have used these medicines, my stomach is not good. I don't have loose stool. There was severe ache in my stomach overall and now it is on the upper part of the stomach. This pain is also travelling to my back. I have this pain on both front and back of my body at the same spot. It isn't a continuous pain but re-occurring. What should I do?