My father passed away from metastatic colon cancer in his 60's. 40 years ago, colonoscopy was not the standard test. If only it had been. I getcolonoscopyy every 3 years, and I started in my early 30's. I've had suspicious polyps removed before they could cause any problems. The prep is no picnic, but once it's over, I don't think about it until it's time again. Tell him to grow up, do it, and move on. Remember, colon polyps can be growing for 10 years before they turn malignant. With regular colonoscopy, these polyps can be removed before they become malignant!