Stomach pain , belly button area

For the past week, I have had pain in my stomach, at the bellybutton area (a little above and a little below)about 2-3 hours after every meal. It feels like I have to go to the bathroom, but I have to push very hard, and I have hard stools. This has never happened before. After I poop (with difficulty), the pain then goes away for the most part, until the next time I eat. This happens 3 or 4 times a day. I went to an urgent care clinic, where the doctor said that he did not believe it was appendicitis. What could this be?