Yep test early. I wouldn't do the poop in a box kit. Falses on both sides of the scale. But it is better than nothing, I guess. One of my clients is the best Colorectal surgeon in the area. He says best to get the scope on the initial exam. It's not as bad as most would lead you to believe. I've had two over the last 7 years. Prep was no big deal, other than not eating. I had a worse relationship with the toilet when I had food poisoning.
Try to get your exam for early Monday morning. Prepping over the weekend is preferrable