Thank you for having the courage to speak so candidly about your crap. In his book , gastroenterologist Dr. Anish Sheth calls the pleasurable sensation you describe “poo-phoria.”
Poo-phoria occurs when your bowel movement stimulates the , which descends from the brainstem to the colon. The vagus nerve plays a role in several bodily functions including digestion, and regulating heart rate and blood pressure.
When stimulated, it can cause a number of reactions such as sweating, and the chills you describe. It can also drop your blood pressure and heart rate, causing the lightheadedness that “can lend a sense of subli me relaxation,” Sheth and his co-author write. If your poop suddenly overstimulates the vagus nerve, it can even cause you to pass out on the john in a horrifying phemonemon called .
The poop authors write that it tends to take a particularly “large mass of stool” to trigger poo-phoria and its vagal-nerve-induced feelings of exhilaration, intense relaxation, and goose bumps. Poo-phoria can be addictive, the authors warn, though they don’t elaborate on how addicts manipulate their poo to make it especially big.
Bottom line: A particularly large bowel movement can trigger the vagus nerve which, in turn, can drop your blood pressure and heart rate, and give you the chills.