Your appendix stores samples of good bacteria so it can repopulate your digestive system in case they are wiped out entirely by diseases such as diarrhea. – WTF Fun Facts
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5011360/
Diarrhea
WTF Fun Fact – Civil War Honor Code
Dysentery and chronic diarrhea were so prevalent during the American Civil War that there was an honor code among soldiers: you couldn’t shoot a man while he was defecating. – WTF Fun Facts
Source: https://www.thecut.com/2016/06/diarrhea-is-the-wartime-enemy-no-one-mentions.html