I have doubts that an insect sting can be serious enough to cause internal bleeding. Some googling seems to confirm it; you might just suffocate if bitten in the larynx [Paparella 2007]:
or just have generic symptoms if bitten in the esophagus (this is a wasp sting, note, and I think in a patient allergic to them).
Swallowed a nail as a kid, got nothing but a trip to the ER and the embarrassment of an entire staff of people waiting for me to poop. I didn't know I needed a full dozen to win the prize!