dangerously thin

I am 88lbs and 5'5. i have horrible stomach problems mainly inlcuding my colon and defecating. I cannot "go" without the use of laxatives/stimulating the colon. I dont know how to gain weight anymore as i seem to be intolorant of everything i put in my body. I have tried protein powders, supplements, boost, ensure, lots of fats like nuts, butter, shakes, carbs, breads, etc. it all just packs in my little stomach, making me look like im 4 months pregnant, and after days of not going, i need laxatives.....is there any hope to gain weight for me? I dont want to be on a feeding tube Tweet