The worst time to divide bamboo is when it's shooting. Messing with the new shoots is a guarantee for killing them. You need to wait until late fall or winter when it's fairly dormant. And you can't just "cut it," when you do want a new plant. You need to identify an established culm and make sure you dig out a decent sized rootball along with the culm.

What about an emergency situation? I've got several shoots that have popped up in my vegetable garden. I obviously need to get them out of there, and plan to relocate the entire plant. I was going to try digging up the original plant, then digging a line down the line of shoots and trying to get the whole thing, then move it to a more appropriate spot.

julianna-
See my answer to this in your other post. And if you decide to move it, you can only move the main plant. Digging up long rhizomes will not likely work and they're not needed. You can pull them out after they're severed, or just let them die in the ground; severed rhizomes don't regenerate unless they're very well established.