Hmmm... I had no such problem. But here is what I did which might be the reason.
One week before colonoscopy, I ate only vegetables, whole grain bread and fruit. No meat, no eggs, no dairy. After the colonoscopy, I slowly added eggs, yogurt & fish to my diet for about a week.
Now I am nearing end of my 70’s and the doc said no more colonoscopies necessary for you.
I had one at 79 definitely didn't want to see me again. Only reason I insisted on having one is my doc kept saying records said I had one recently and I knew I hadn't.