Its because you have no fat reserves and your body is telling you to eat or you will die.
Try a fat fast or some sort of carnivore mono meals type of eating if you want to put less stress on your body for healing purposes.
Horrendous gut issues is not a well defined medical condition. Have you been to a doctor so they can sort out what’s going on?
Sometimes doctors can be mired in dogma when it comes to treatment, but something they excel at is diagnosis. 99 out of 100 they can tell you what’s going on within one or two visits.
Just Thrive has multiple supplements that are absolutely life changing for gut health. The investment is worth it. The probiotic, prebiotic, gut fortify, and IgG. All of the products you can take on an empty stomach while fasting. They are a wonderful company with life changing products!