[Lani]

Chemo does "a number " on the GI tract so I guess it is the most likely culprit, but just remember there are other drugs, common ones you may still be using, that can cause GERD as well ie, norvasc, a calcium channel blocker commonly given for high blood pressure, can cause the gastro-esopageal sphincter to relax and allow stomach contents with acid to reflux into the esophagus. A quick review of your meds and their potential side effects with your doctor might possibly enable you to try to switch to different meds and get off the anti-GERD drugs, which have side effects of their own eg, PPIs may have adverse effects on the kidneys and bones(osteoporosis) and make one more susceptible to C. difficile diarrhea.

If no other potential culprits are found, it never hurts to be aware of the different side effects of the different groups of antiGERD drugs so you can look out for them.