I Am Losing Weight Roughly Now I Weigh Between 88-90

I am losing weight roughly now I weigh between 88-90 lbs. I have had a colonoscopy & the scope down my throat. Nothing showed but my Dr.'s were concerned about my decrease weight loss. Normal weight was about 108-110lbs. At this point over a month since my colonoscopy my weight has not improved and no word from any Dr. to date. Who can I see to discover what is going on?