What else should I ask my doctor to test for? TW for regurgitation/v*mit

Sorry if this isn't the best sub for this, I couldn't find a better one. If you know of one please let me know.

I just had a colonoscopy and endoscopy and everything came back completely normal. I honestly can't believe it considering all of my symptoms. Still waiting on celiac biopsies though. Assuming those are normal, what else should I ask my doctor to test for? I want to be prepared for my next appt with them.

Symptoms:

• Food regurgitation several times a week. I had the worst one happen last week when it almost went all over my keyboard while I was working and I caught it in my hand. I don't even know its about to happen. It just does it out of nowhere. Usually no acid in it either.

• At least once a day after eating I will have diarrhea (2-3 times)

• Crazy bloating off and on - I look pregnant and my stomach will be so hard

• Smelly awful gas

• Deep burping after meals

• Vitamin deficiencies - so far tested for B12, Iron, D and A. All are low. I thought it was due to my hypothyroidism which I am now being treated for, until the Vitamin A came back low. They said hypothyroidism can't cause low vitamin A. These deficiencies give me all sorts of their own symptoms.

• A few months ago I had crazy nausea and lost 25 pounds in about a month. Nausea has since went away and all the weight came back on.

• Sometimes I will get adrenaline rushes/chills before having to go no 2.

Already tested for -

Allergens - extensive testing all negative except for honey (bee propolis)

Celiac blood test was negative

Diabetes - negative although I am having off and on reactive hypoglycemia

The GI symptoms are tolerable for me (probably bc my other symptoms are so bad), but the symptoms from the vitamin deficiencies are horrible. I take a ton of oral vitamins and nothing helps. Only thing helping some is B12 injections and I will probably need another iron infusion. I don't think my body is absorbing the vitamins in my digestive system.