What Causes Stomach Pain And Fainting After Having Bowel Movement?

I fainted early yesterday early morning (Sunday)after having stomach pains and during bowel movement , I started to feel queasy, cold and clammy, headache, started to feel dizzy and all of a sudden I found myself on the side of toilet -landing on the metal magazine holder(now have a very bad mark scar from the metal design of that magazine holder), I must have been out for a while since the mark is pretty deep from the metal magazine holder. I called my primary care today and they scheduled a cat scan and they are suppose to give me the result tomorrow. This is the 3rd or 4th time this has happened and I m getting scared as to what is causing it. It s always after not feeling well the day before, having stomach aches, going to the bathroom for BM and feeling of impending doom,etc.. my chest hurts, my rt arm feels numb, I m irritable, and feels like my head is going to explode. Please help! Do I have a heart issue? I believe I have family history of stroke, heart disease... thanks for your help!