Hello and welcome. I am Kitt.
Regarding your question, if your gas is painful the pain could cause you to feel lightheaded.
I know that from experience with colon preps for endoscopies but that is just my experience.
Moderator Anxiety ~ Panic Disorders
Dx: Anxiety/Panic, Depression
"If you doubt you can accomplish something, then you can’t accomplish it. You have to have confidence in your ability, and then be tough enough to follow through.”