I caution about using Boston Children’s or, for that matter, a “top specialist.” The most likely recommendation from these sources is psychiatry (they are very busy with more easily diagnosed serious issues). The tendency is to dismiss symptoms as psychological and I would not accept that without more investigations. For starters I would consult a functional medicine or integrative medicine doctor.
Has anyone tested for food allergies or celiac? Even without the testing, he could try an elimination diet with a nutritionist via functional medicine, or even just try giving up gluten and dairy. To state the obvious: all of this testing does not mean there is no physical issue. (I assume Crohn’s and ulcerative colitis were ruled out.)
Since he takes meds at night (what meds? this is important info!) I wonder about the morning after effects. For instance, trazadone causes nausea for a lot of people. (It is also not approved for under 18, leading me to wonder what drug is being used.) Also Ritalin can cause nausea. There are other options for ADHD. Is he seeing a specialist for that? (Just google his meds and nausea…)
Maybe consult with a psychiatrist to do a “med wash” (stop all meds, gradually and safely) to see if the nausea improves.
Some SSRI’s cause nausea too.
I have two kids who had/have this kind of issue. One was referred to psychiatry but ended up having celiac and had colitis at the time we were seeking help. One is on Lithium and despite am nausea, has to stay on it. They tried zofran (anti nausea med) for awhile but it is intended only for short term use.
I completely understand the barriers to work and school. Your son should have accommodations at school via a 504 plan, accommodations for SAT and ACT, and accommodations at college. This will require a diagnosis (including psychiatric if that ends up being the answer, but I doubt it) and documentation from a professional. Online non-synchronous classes in both high school and college can be helpful too. Our high school accepted them and they gave flexibility for health issues. vhslearning.org
One of my kids teaches/advises at a college and deals with morning nausea with one student. The student only takes classes that start later and was exempted from a required 9am class, doing independent study as an alternative.
Many kids with anxiety at this age, improve over time, and there are supports available to help him function at his best.
ps McLean Hospital, top in the country for psychiatry, does not prescribe sleep meds for adolescents, in our experience- even for kids who are hospitalized. Your son could get off the sleep med safely and try CBD gummies and melatonin, which McLean’s uses first. His brain is developing and I would ask doctors (including psychiatrist) or research the effects of sleep meds used so frequently, on the adolescent brain. I have no idea, but just a thought based on what McLean’s suggested to us.