Executing a Bash Script Function with Sudo

I have a script that does a number of different things, most of which do not require any special privileges. However, one specific section, which I have contained within a function, needs root privileges. I don't wish to require the entire script to run as root, and I want to be able to call this function, with root privileges, from within the script. Prompting for a password if necessary isn't an issue since it is mostly interactive anyway. However, when I try to use sudo functionx, I get: sudo: functionx: command not found As I expected, export didn't make a difference. I'd like to be able to execute the function directly in the script rather than breaking it out and executing it as a separate script for a number of reasons. Is there some way I can make my function "visible" to sudo without extracting it, finding the appropriate directory, and then executing it as a stand-alone script? The function is about a page long itself and contains multiple strings, some double-quoted and some single-quoted. It is also dependent upon a menu function defined elsewhere in the main script. I would only expect someone with sudo ANY to be able to run the function, as one of the things it does is change passwords.