I'm a type 1 diabetic. a year now i get diarrhea, only at night. why am i only getting it at night? been tested for celiac, ibs, & crohns but not it.

Diarrhea: If you are diabetic you did not mention if your taking medications. A diabetic medicine called metformin can cause diarrhea and maybe worse at night due to being relaxed and possible less sphincter control.

Long standing T1DM: Unfortunately, there are complications of having diabetes for a long time. It can affect the nervous system and the way it controls your bodily functions. I suspect if other testing was negative it could be related to this type of nerve damage. Talk to your doctor to address further.