can sinus drainage upset stomach?
<answer> Yes <context> Sinus Drainage & Stomach Problems. One of the primary results of sinus congestion is drainage. Sinus drainage is expelled in two basic ways: through the nose and the back of the throat. When sinus drainage is expelled in back of the throat, it is referred to as postnasal drip and can cause stomach discomfort. (Jupiterimages/Photos.com/Getty Images) As the sinuses drain into the back of the throat, the mucus makes its way to the stomach causing an upset stomach.