For instance belching. More than once, while walking seemingly alone in a quiet neighborhood, I will have a sudden belch. I have learned to look around to see from where my unconscious mind has picked up the presence of another human being. There is always someone that I would have either not noticed because my mind was occupied with the task at hand. Like someone working on a car in a driveway, and I see that person once I pass.
Flatulence is somewhat similar in nature.
It is however triggered by something in my mind. It is especia lly severe after my evening meal while studying at my computer. It really does not matter what I ate. There are some foods that give me a more severe reaction as far as bloating and odor. My active mind and apparent nervousness is the real problem.