Euphemism for diarrhea

I've recently been having diarrhea and may be calling in sick to work tomorrow. I work at a small company, so typically this involves emailing my manager and team with something like this:

Hi team, I seem to have caught the flu that's going around my son's day care. I'll be working from home today so I don't get anyone else sick.

In this case I was looking for a similar way to communicate with my manager/coworkers without grossing them out, but still making it clear that it's really in everyone's best interest for me to stay home.

Solution 1:

Upset stomach

a disorder of digestive function characterized by discomfort or heartburn or nausea

Edit — As seen from the comments, this is actually an informal term for Dyspepsia.

Dyspepsia, also known as indigestion or upset stomach, is a term that describes discomfort or pain in the upper abdomen. It is not a disease. Dyspepsia is a group of symptoms which often include bloating, nausea and burping.

Diarrhoea often follows Dyspepsia. So unless you need to provide specific details about your stomach condition, it's best to use upset stomach. I wouldn't like to hear from an employee the words like Diarrhoea, the runs etc. The imagery is off putting.

Note: Diarrhea isn't always contagious. The infectious diarrhea is called Gastroenteritis or stomach flu*.

_{^{*Info gathered from various posts on this page. comment1, Malvolio's answer, comment2, Martha's answer, comment3, Dave's answer}}

Solution 2:

Following on from what Dan Bron said, yes, it can often be euphemistically, albeit informally, called the runs. Similarly, it can be called the trots.

the runs/the trots informal

diarrhoea

Source: Oxford Dictionaries Online