The medical condition of sending too many text messages or messages that are too long. Applies to any text-based system including cell phone texts, facebook messages, email, etc... This common ailment usually occurs when a friend is hyped up on energy drinks or has had too many alcoholic drinks.
Guy #1: "What's up with that message you sent me last night?"
Guy #2: "Sorry, dude. I get textarrhea when I'm drinking and it's like the words start writing themselves."