Anyone else have this stomach ailment?

Occasionally (usually in the morning on an empty stomach, but not always) my stomach cramps up in horrendous knots and I double over and dry heave uncontrollably. This happens while I'm in the bathroom, and I have to put the garbage in front of me in case my stomach isn't empty. Over the next hour or so, I will cramp up again repeatedly every few minutes and have to return to the bathroom, where not much will happen. I haven't gotten any help from doctors that I've told about this.