Re: Question about a Barium enema
The only thing I can think of is a barium enema is less invasive... and I guess some hope they will see what they need to see in the barium enema. If nothing is present in a barium enema, and there are no symptoms of any problems (as you say its just routine and he has no symptoms), then there really is not much need of doing a colonoscopy. Sedative is needed during a colonoscopy and your husband would be "out of it" for most of the day. (Not sedated for most of the day, just "giddy"). The barium enema requires no sedative. It's really personal choice.
However, if they plan on doing a colonoscopy anyway, it would not make any sense.