Is frequent gas in the stomach also a medical condition?

I've been having a lot of gas in my stomach lately, so I feel bloated all day.
Even if I eat just a little, I feel full and uncomfortable.
I feel like my bowel function is not what it used to be.
I'm wondering if this could be irritable bowel syndrome
I also want to know what tests will be done when I go to the hospital.
I'm also curious to know how changing my eating habits might help.