I'm worried about getting a colonoscopy because of an article i just read about a study where 20% of endoscopes contain bio dirt after proper cleaning?

Colonoscopy.: it is good to be well read about your health and concerned about what you read, but it is also important to put what is read into context. Colonoscopy has been shown over more than 30 years to be a reasonably safe procedure, with only rare instances of transmission of infection. On the contrary, it can't be life-saving. Don't let this article keep you from having the procedure. Good luck.

Voice concern to Dr.: Tell the Dr about your concern and ask for reassurance - also consider psychotherapy to address this common aspect of OCD dirt phobia. It's well treated by CBT if you try. The risks of not dealing w/ your illness may be much greater than this possible exposure. You take greater risks all the time - choose well. Best wishes!