Dear Dr. Roach: I am a 74-year-old woman. I have an unusual situation for the past few years. When I have my morning bowel movement, I have a sneezing fit and my nose starts running. This happens quite often. I am baffled by this. Have you ever heard of such a thing? — J.O.

Answer: Yes, it’s called defecation rhinorrhea, and it’s more common than you’d think, even if some people don’t realize they have it.

During a bowel movement, the nervous system is in the parasympathetic mode — sometimes called “rest and digest” as opposed to sympathetic “fight or flight” — and that causes dilation of blood vessels in the nose as well as other places, leading to runny nose and a sneeze reflex.