I've Been Having Off And On For Over A Year

I've been having off and on for over a year periods of loose stools that are shiny like they have been cover in oil, a dull pain in my back just below the diaphram I'm a type 2 diabetic that has been well controlled but recently my numbers have been going up, 148 this morning. I'v had a colonoscopy, stool culture and checked for parasites all your basic labs, any ideas to the cause?