Will you be having sedation?
Have you been sent laxatives to take or are they giving you an enema at the hospital?
You'll be booked in then called through to female changing area when they're ready for you. Once they've finished their consent and other paperwork they will give you a gown and some lovely shorts to wear with a slit in the back. If you're having an enema the nurse will administer that.
When you're ready they'll walk you into the endoscopy suite, ask you to take off your dressing gown and lie on the table. It is usually in the centre of the room with equipment positioned around it. There will either be a curtain in front of the door or it will be locked to prevent anyone accidentally walking in.
They'll talk you through what they're going to do and who in the room is doing what, and finish setting themselves up. Someone will bring in the scope they're using for you in a transparent briefcase type box. There will be a screen on a stand so depending on which way you're facing and how awake you are you may be able to watch if you want.
They'll put a cannula in your arm or hand to give you the sedation and painkillers.
Once they're ready they'll ask you to either lie in your left side or on your tummy with your arms up by your head superman style. They'll put oxygen tubes in your nose and a monitor on your hand to check your pulse and oxygen levels, then they'll inject the sedation and things will hopefully fade away.
They will have gas and air available in case you need it, but the most painful part is usually the corners of the colon so with a sigmoidoscopy you hopefully won't need it. But if you do, just ask.
If it is painful TELL THEM. If you want them to pause or stop at any point for any reason TELL THEM. Don't suffer in silence.
With sedation you'll maybe remember all of it, none of it, or parts of it, but either way you'll have been responding to any instructions from staff (e.g. To turn on your side).
During the procedure they will pump carbon dioxide into your colon so they can get a better view. This takes a few days to work its way out of your system so your tummy might feel a bit sore and bloated. Nothing to worry about.
You might bleed a very small amount from the biopsies but that will be negligible. Again, just mentioning so you don't worry it's something sinister.
I assume you've been given leaflets on how they do the actual scope part, so I'm just focusing on the stuff they don't bother to tell people.
Afterwards you'll be taken to recovery to sleep off the sedation (or get dressed if you didn't have any). Once you're ok and they're happy, you can get dressed and walk through to seated recovery where you have a drink and a biscuit before you go home.
If you're poorly from the sedation (e.g. Vomiting) you might be there a bit longer otherwise it's normally about an hour after the procedure finishes you can go home. You might feel a bit out of sorts from the sedation, depending on how you react to it, but you should be your normal self in a couple of days.
Obviously you won't be able to drive afterwards if you've been sedated. Same rules as for general anaesthetic apply, so for 24 hours you need someone with you, no driving, no using machinery (that includes things like ovens) or signing documents, etc.
I think sedation would probably be sensible, not least because it's your first time. If you find it really easy and become a pro at it you may not want it next time.
Good luck, hope you have an easy and forgettable experience!