Hello,

I am sorry that you and your daughter are going through this. I wanted to comment because the way you phrased her symptom, "constant hunger", is how I described my symptoms a few years ago (mine were particularly bad at night and would wake me up constantly). It turned out that I had small intestinal bacterial overgrowth (SIBO) as a result of a colon resection surgery. For people without colon surgery, this condition is thought to arise from an episode of severe food sickness that damaged gut nerves (this is a hand-wavy explanation, if you are curious there are more details elsewhere).

When you say she cannot tolerate 'fruits or vegetables without additional stomach pain and gas', this points to SIBO as well - the sugars, starches, and other oligosaccharides in fruits and vegetables can certainly set off bacteria in the small intestines, and can cause diarrhea, constipation, or a mixture of both.

Even if she was breath-tested for SIBO and that was ruled out, these tests are notoriously unreliable. Both false positives and false negatives are common. Treatment for SIBO usually involves several rounds of special antibiotics, but these are also rarely successful the first time and can be unpleasant.

If I were in your position, I would try a diet that avoids the foods most likely to set off SIBO like follows to see if it moves the needle one way or the other. Keep in mind that you may need to keep the diet for 3-4 days for to see the results, if you don't have results after 4 days, it is probably not bacterial overgrowth that is causing the issues. I am also happy to be more explicit in what she could eat, if you are having issues figuring out diet.

Absolutely need to avoid:
All gums - guar, xanthum, carob bean, etc. These compounds are sadly everywhere , so you need to check extra well.
Other starches including potatoes, rice, oatmeal, and even wheat, except for breads, see below etc.
Vegetables
Yogurts or anything else with live bacteria

Okay in small doses (small may depend on the person):
'White' breads that have been yeasted
Fruits or fruit juices, again small doses
Mission flour tortillas, although they have not been yeasted, seem to be well tolerated for whatever reason

Again, happy to trouble-shoot if you are interested in going down this route, but do not want to spend my entire morning yapping into the void if you are not.

Good luck!