First, thank you for your national service as a retired military man. Coming up on July 4, hats off to you and your fellow service personnel, past and present.
Regarding your GP's recommendation for a colonoscopy, the importance of one is driven by your age and family history of colon problems. I don't have sodium intake restrictions, and have had twp colonscopies. For the first, I was a good patient and followed the Go-lytely protocol. Downing a gallon of that stuff was nauseating and miserable, not to mention the amount of time in the bathroom. For my second colonscopy, I had a two-hour colonic session and did not tell the doc. During the exam, the doc complimented me on my 'prep' and how well I had followed the fast and Go-lytely routine. What he didn't know won't hurt him. There is a hospital in Connecticut that now offers colonics immediately before a scheduled colonscopy. If your colon therapist knows what he/she is doing, and is willing to spend more time with you for a few extra 'fills', I think your prep will be as good, if not better, than with Go-lytely. That stuff is pure wicked.
Hagar, have a good Fourth!