Lower Left Abdominal Pain After Eating

I'm wondering if anyone has experienced this pain before, and might have any ideas on what it could be, or what is causing it.
I'm experiencing sharp pain in lower left abd, after eating meals. Usually, only if I eat a large meal, if I snack it rarely happens. It happens almost immediately after eating. If I press hard on the area of pain, it helps it. It doesn't hurt if I am sitting, or laying.It hurts very bad, if I walk or stand. The pain is approx 2 inches left of my bellybutton, to 3-4 inches below that.
Anyone? Anything? I'm lost, confused, and drs don't seem to think its a big deal. I had an upper g i last week, and I'm fine. Although I don't know what an upper gi will tell them about my lower abdomen.
Thanks for reading, and hopefully helping!!
Mrs. Ev Tweet