As much as the prep sucks for the operation, I would do it all over again without hesitation. A few months after the September 11 attack I went in for a endoscopy and it, ahem, saved my a$$.
They removed a polyp and it tested as precancerous. Family history had me go in and darned glad I did. Been in since then and no problems.
Unfortunately the doc was Iranian and I am not sure what words came out of my mouth right before I went under...