Originally Posted by
7deadlyplugs
H2S is also why farts smell.
As far as diarrhea on your own hand- not too far fetched: the anal sphincter is a very smart muscle; with the proprioceptors it has, it can easily distinguish incompressible solids (e.g. poop) from compressible gasses (e.g. farts). That's how you just "know" when it's okay to let something rip. Trouble arises, however, when liquid is added to the equation: liquid, like solid, is incompressible. Therefore, your sphincter could send a message to the brain saying, "Okay! All's clear, solid poo comin' out!", when in fact it's really nearly a liter of messy, liquid squirts.
Hope this helps!"