I have been passing sulfur smelling gas for about two weeks and have a rash on my arms and chest. I was taking a prescription for Polyethylene Glycol 3350. When I called the pharmacist he said to stop taking it. It sounded like an allergy reaction. The doctor said it would work its way out of my system, but neither has happened as of yet. Do you think this could be from the prescription and what else should I do??