Yeah, someone's just having a bit of fun.

Unless there are multiple people registering patients, and one of them doesn't use punctuation.

It seems very likely that this drop-down menu was not populated by one person, or perhaps was even populated by multiple databases written by very different people with highly disparate levels of grammar knowledge - maybe even different first languages.

Or someone thought it was funny, like you said. I'm not here to judge.

The only cure for "unable to eat diarrhea" is to put the patient into an induced comma.