I'm not sure about the Maalox, but I do know that Tums were on my safe list.
I took Malox in my late pregnancy. I had severe heartburn and my doctor said it was fine.
you can fart and burp a lot...LOL sorry but that's what most Dr's will tell you. Avoid any unnecessary meds is what they'll suggest, and avoiding gassy foods can sometimes help you...but if it's really bad call your doctor to ask specifically about each one. Malox should be okay to take so it surprises me that the pharmacist would say that...maybe call another pharmacy?