You settle down on the toilet and get ready to do your business, when all of a sudden you’re met with a distraction: your nose starts running. You don’t have a cold, your sinuses aren’t bothering you, and you didn’t have a runny nose when you headed into the bathroom. So what’s going on? The unusual occurrence actually has a name: defecation rhinorrhea. It turns out that the bowels are regulated by a complex coordination of nerve signals. The parasympathetic nerve fibers in your pelvis are responsible for triggering contractions in your lower colon, which move waste through your digestive tract and eventually evacuate your stool. Those same nerves also regulate the blood supply to your nasal area. So, when your body is prepping to poop, it also fires up nerves in your nasal passages, which can cause the blood vessels in your nose to widen, resulting in a runny nose. The bottom line —your runny nose while pooping is a normal physiological response.
