For about three weeks now, i've had severe diarrhea, but only between the hours of 1am and 3am. i will be seeing my doctor, but not for another week. what are some possible diagnoses?

Colitis: You have colitis infectious or non infectious. Hope there is no blood in your stool. Until you see your doctor focus on your diet, avoid dairy products , orange juice, and green salads, increase your fiber intake. You may send your stools for culture until you see your doctor.

Change routine: You have diarrhea 1-3 am. Seeing your doctor will be important. As long as the diarrhea is self limiting and you are not dehydrated. It could be what ever you are doing before bedtime. Look at anything you are eating or swallowing. Sometimes products have ingredients that your body may not like.