Guaifen-C Side Effects: I am taking the liquid prescribed by my doctor and am experiencin http://www.medications.com/effect/view/20228 I am taking the liquid prescribed by my doctor and am experiencing pain in my stomach. I was wondering if anyone else is having this symptom. I am not taking the exact same medicine, but another that also co Mon, 16 Jul 2007 22:11:39 -0400 http://www.medications.com/effect/view/20228?item=762 I am not taking the exact same medicine, but another that also contains guaifenesin. I have stomach pains almost daily (very mild, though), but I'm not sure if it's related to the medicine or not. http://www.medications.com/effect/view/20228?item=762