GERD sucks... I've got it really bad, and when I don't have any OTC meds handy, it can get really really uncomfortable. If you have a GERD "attack" and are unable to get to any meds, try drinking some whole milk- it coats the esophagus with a mucous, and tries to normalize the pH in your stomach.

But yeah, if you've got those ailments, I don't see why you couldn't get a card. Best of luck!