When we posted about the IgNobel Awards last week, there was one intriguing study we didn’t mention. It’s titled “Colonic gas explosion during therapeutic colonoscopy with electrocautery” and, yes, it’s about butts exploding.

Did you know 20 people have experienced a colonic gas explosion while getting a colonoscopy? All of these cases occurred between 1952 and October 2006, and one of them was fatal. Meaning there’s at least one person out there whose cause of death was “butt exploded”. We’re just surprised it wasn’t Vince.

According to a team of researchers led by Emmanuel Ben-Soussan (who last week was awarded an Ig Nobel prize in medicine for advising doctors on how to avoid gut-combustion), an explosion of colonic gasses requires three things:

1. The presence of combustible gases (hydrogen and/or methane)

2. The presence of combustive gas (oxygen)

3. Application of a heat source

Your bacteria provide the first two; electrocautery — a technique that uses heat to remove potentially cancerous intestinal growths known as polyps — provides the third. [io9]

This is one of the reasons why patients undergoing a colonoscopy have to drink the big jug of salty liquid to clear out their intestines. It’s not just because doctors love to make you swallow a big gulp of salty liquid . . . er, let’s move on. The colonoscopy prep cuts down on those two flammable gases.

The average person produces one to four pints of gas per day (only some of it flammable), and a colonoscopy explosion would only require a concentration of methane and/or hydrogen exceeding 5% or 4%, respectively. In our natural state, the concentration of these two gases is often higher than that explosion threshold, so keep that in mind before sitting on a barbeque grill we guess.

Also, we’ve made this helpful comic to illustrate a colonoscopy explosion:

FACT.