“There is a particular nerve in our body called the vagus nerve, that helps regulate certain things such as digestion. So let’s envision (not literally!) a scenario where you’ve been holding in a big load of poo inside and you just get home and are about to let it rip!
The first few seconds after you unload, it’s like you are overcome by a heightened sense of calm and release, isn’t it? This phenomenon, perhaps one of the greatest feelings in the world, is driven by stimulation of the vagus nerve but a really massive poop!
Stimulation of this nerve causes your heart rate to be lowered, drops your level of blood pressure after holding it in for some time and sends a momentary feeling of calm through your whole body. The feeling is very similar to a dose of dopamine and according to scientists, can even be addictive!”