Two weeks ago I woke up in the middle of the night to an incredible urge to use the bathroom. I was up all night until the early morning hours with explosive diarrhea. I would have to get up every 5 minutes to go to the bathroom. Since then I have had it every day, all day and all night. I might get a 4 to 5 hour break before it hits again. I'm drinking lots of water and am not experiencing dehydration yet, but I'm very tired which I think is due to lack of sleep. I've tried over the counter medicines, but they don't work. It doesn't matter what I eat. It will pass through my system unabsorbed within an hour after eating it. I've been on the BRAT diet and it all passes through me like water. Nothing is helping. I was thinking of seeing my general doctor first, but I don't want to waste any time, so should I go directly to a gastroenterologist? What type of tests should I be prepared for?