I'm sitting at a computer booth in the library. A few moments ago, I overheard this from a nearby booth:
Guy on cell: "I've got the runs, dude. (slight pause) So what's up?"
I guess he was right in changing the subject. At the same time, I feel that if you're going to mention diarrhea loudly over the phone, you gotta commit to it. "I've got the runs, dude." by itself is kind of an odd, floating comment. Why not anchor it down and give your friend and the eavesdropping public a little bit more information. A "Man, I really shouldn't have eaten 10 tacos for breakfast" or something of that sort to liven things up a bit. Then it would have potential to be a funny, little anecdote. Otherwise, big whoop, no one cares.