Are you from the UK? If so, what laxative have they given you? If I were you I wouldn't go to work as It will give you the runs. A laxative before a colonoscopy id designed to clear out your system. If you can take the day off do!
If Its for a colonoscopy it will prob be something called citramag but if its a sigmoidoscopy it will prob be a fletchers enema. I'm a nurse so i know (i'm not sad and know this for the sake of it!!!!!!).
Hope you get on ok, let me know how you gt on
Victoria (was tori but decided to use my proper name!)