I get this! It seems to have had multiple causes.
It seemed to be gone when I first got my gallbladder out, but then it came back. I was very constipated at the transverse colon. Nothing could pass thru that sharp turn to get into the sigmoid colon.
Strangely when I corrected my 1/2 inch of leg length discrepancy by standing with the shorter leg on a book, I started getting relief of my pelvic/groin/anterior leg pain after about 45 minutes, and then after a day or two, my constipation resolved. I always use Miralax, but it had not been as effectively lately. Fixing the pelvic muscle and nerve problems caused by standing all day with my hips at any angle seems to be the mechanical change needed to get my colon working! WEIRD.
I read part of a book on line that talks about this situation. OSTERGARD'S UROGYNECOLOGY AND PELVIC FLOOR DYSFUNCTION, by Alfred E. Bent, Geoffrey W. Cundoff, and Steven Swift. Chapter 9, page 139.
Good luck in your search.
I get this all the time espically when I am on my period. Not only do I get it when i eat i still have it after i go to the bathroom. I see a range of specialist for other reasons but i always ask them and they can never give me a reason. I dont ever get bloated any lower, it is not painful but i have it pretty much everyday. I am sorry i cant dont give you a reason why but just know that your not alone with it
Did you do any tests check ups?
There can be many reasons , your bloated upper stomach is due to constipation as you mention it usually happens after you eat a big meal. As most physicians would suggest to start eating smaller foods but more often so your stomach can digest it faster, drink more water per day(warm water), buy fibrogel it's available w/o prescription from the doctor(it's for constipation take one in morning and one before sleep), try to stay away from coffee,chocolate,fast food,junk food.
Do above for 1 week if you see no improvement go see a doctor and ask him to test you for digestive disorders,thyroid and bacterial overgrowth