EXCITING UPDATE:
I started with a new GI doctor 6 weeks ago. She skimmed through my list in first Mayo posting, and proposed new approach to try.

She prescribed nortriptylene for my belching and gas, telling me she has had good feedback from IBS patients in the past. I started with 10 mg / day, taken at night due to potential drowsiness. The instructions call for raising the dosage 10.mg every 7 days until improvement is noticed, capping at 50mg. This is minuscule dose as compared to when this is prescribed for depression.

I had not been sleeping well due to intestinal and bladder discomfort for over a year, getting up 4-6 times each night after only one time usually for 50 years. Within a day or two I cut down to two times, and have been tracking carefully since, most nights I get up 2 times, with a couple single trips, and a couple 3 trips ( never more). I also noticed right away a reduction in belching, mainly supragastric I think, and intestinal gas discomfort. I also noticed a change in my chronic headache frequency, which used to be much more severe and frequent before, now I have logged two days of zero, one severe one, and most others fairly so minor that I consider after all these years to be a non issue. I used to have 3-5 acute 1-3 hour periods of very uncomfortable belching each week; in 5 1/2 weeks I have only had one, that lasted about an hour. I still have some gastric (maybe not a lot more than healthy normal) and supragastric belching, but maybe a reduction of fifty percent, so subjective it is hard to be sure, as I was not carefully logging before January for all these years.

I started with the 10 mg, but took it for two weeks instead of one since the change had been so profound, then decided to try 20, and now after 3 weeks of higher dose, have decided I may not need even 20 because it didn’t seem to make any difference when I increased to 20, in my symptoms.

She also advised trying speech therapy as another approach, as supragastric belching is a learned behavior, not a natural one like gastric belching. I have not started yet, but intend to right away, finally found a good therapist. I have read in reputable medical articles that CBT has also been used successfully, but plan to stick its the speech therapy for now, which may have a lot of similarities to CBT in this context. She gave me a referral to a psycologist that does CBT as well, but I am going to wait and see if I really need more help after I work with speech therapist.

I started using Azastline for constant nasal congestion about a week before the above treatment, and there is a possibility that it is helping as well as a no longer have to swallow mucous constantly, possibly along with air….. I have worked with ENT and allergist md within the last two years, finding both OTC steroids ( Flonase and something else) to be ineffective, and was told to consider surgery, which I avoided due to the fact that sinus surgery has poor permanent effect , according to the two doctors. My new ENT I found in December suggested the Azelastine, and it continues to work consistently 24/7, a huge relief. I felt like nasal congestion pressure also contributed to my headache and sleep issues.
Other side effects of nortriptylene besides drowsiness ( I have not felt more drowsy than my norm before treatment) are dry mouth and constipation. She encouraged me to try Citrucel oral tablets 6 grams of fiber a day, along with high fiber diet and plenty of water, and although my habits have changed, I have been regular daily. She has found that the powdered flavored fiber supplements can cause bloating, etc. Unfortunately , tablets are pretty pricey. I would be concerned that these side effects could become more of an issue if I have to take more nortriptylene, so I am hoping these positive changes continue.

I plan to provide another update after a few months have gone by, to report on any further changes positive or negative. I wanted to post right away in case someone else might profit from this info. I would also be interested I hearing from anyone has has tried nortriptylene for GI belching regarding efficacy and also if others have found it to help with sleep in this tiny dose. Also, has anyone tried speech therapy for belching?

Talk to your doctor(s) if this might be helpful for you too! This is definitely the most profound improvement in my health in a long time ( last one was using CBT DIY 5 years ago to resolve an insomnia issue that I had for over 20 years, in about 9 weeks (!), with that help of a PAC sleep coach.