@ alto
Spinach can contribute to bloating and so can protein bars. Most protein bars contain some type of nuts or peanuts (peanuts are legumes and not nuts) and also contains some sort of sugar. Sweets can cause bloating .. sugar substitutes can be worse triggers than actual sugar. I also get bloating with dairy products and whey.

I was told after my open abdominal/thoracic surgery that I would belch and pass gas and not bother with anti-gas products .. they won't help.

Because of a swallowing problem … achalasia … I swallow air and that does not help the problem. Swallowing exercises can help … such as those for stroke. I discovered that as I watched my mom recover from a stroke. I did the exercises along with her. The exercises will help even if you have no obvious swallowing problem. Also breathing exercises help .. breathe with your diaphragm. Exercise in general .. like walking .. will help.

Moist heating pad or hot water bottle held on the area may help along with gentle massaging. Lying on your left side can also help with bloating.

None of this is a cure, but are ways to ease the problem.

What to eat … whatever bothers you the least. Everyone is different.

Best wishes,
ZeeGee