Two colonoscopies six months apart?

My Dr. did a colonoscopy in may. He diagnosed me with colitis and started me on medication for the condition. Months after starting the meds, I was still having the same old problems. I explained this to the Dr. who seemed to not care or attempt to try anything new to help my situation. I changed Dr.'s The new doc has decided to test for Celiacs and ordered and endoscopy. After the endoscopy, the new doctor had been looking through my file and asked why I was diagnosed with colitis. I told him that after my colonoscopy, my old dr, had decided it was colitis. The new Dr. then stated that the biopsies from the colonoscopy that the old dr preformed had been normal according to the report from my medical file and then told me he wanted me to schedule another colonoscopy. Why would he schedule another colonoscopy when the first one was done six months ago? What would be the purpose of this? Other than getting paid. I am concerned that having these colonoscopies so close together can not possible be good for my health.