What do you mean by "laxative" do you mean an over the counter one like milk of magnesia or ex lax? Or are we talking PicoSalax?
Because if it is the Pico or Magnesium citrate, do not venture too far!
I had to be completely empty for my hernia op. So they gave me the Pico, it took about four or five hours to take affect on me (I tend to be constipated at the best of times) but when it hit, Oh Boy!
So, judge for yourself based on your past experience with regular laxatives if it is one of those. But if it is the industrial strength (as I like to call it) be careful how far you venture from the nearest bathroom.
PS. Congrats on your op! I will keep you in my thoughts, good luck!