Why does spicy food burn on the way out?
When you eat something spicy, the spiciness of that food often comes from the compound capsaicin. As SciShow explains above, capsaicin binds to your TRPV1 receptors. ... By the time the digested food reaches your anus, there's still capsaicin in the food waste and your butt feels the burn.
Why does vindaloo make you poop?
When capsaicin triggers the TRPV1 receptors in your intestines, it makes your GI system cramp up. Basically, your GI system is stimulated more than normal and gets things going faster – making you need to poop ASAP.