I'd take the whole day off yes.
Firstly, you will have to do a little diet they give you a sheet with what's allowed a few days before. Then this can vary but you drink this stuff the night before. About two litres. It tastes awful but a tip is to put in the fridge and drink with a straw. You can add lemonade too. You wouldn't be able to eat. This will make you run to the toilet a lot. Plenty of moist wipes. You get to the point where water is just coming out.
At the hospital you will have a canula put in. You get given some underwear with a flap in the back and two gowns. One on like a dressing gown keeps everything covered. Normally a bad or locker to keep your clothes in.
You lie on the bed on your side and they just open the little flap. Pop the tube in no one can see anything. You will be given sedation anyway by this point and everything feels fine. At points you have to lie on your back. You get to see your bowel in a massive TV

. Doesn't last long, some people fall asleep. I haven't because I want to see. They take you to recovery where you have tea, toast and biscuits. Then you on your way. Often I have a bloated tummy so windy the rest of the day.
Honestly, the prep is the worst part. But take the sedation and if you need gas and air. They will be a nurse right next to you, often holding your hand if needed if you feel scared.
Hope this puts your mind at rest.