Why do you want to bounce your drum loop? You can leave it as MIDI as long as you want right up until your final export so you can edit the parts in PRV as needed. If you want to conserve computer resources you can just hit the track's Freeze (looks like a snowflake but read up on it in the manual a bit so you know what it does exactly) button and it will be exactly like bouncing it to audio EXCEPT you can hit that Freeze button again and it will turn back into the original MIDI track if you want to edit it again.
But if your computer is good enough you should have too hard a time having one MIDI drum track going while you record/mix/etc. I leave my MIDI drums totally active in my projects all the way through until final export.
Now if you have a whole bunch of MIDI clips making up that drum track then yeah... you could do "bounce to clips" but all that does is turn all those small MIDI clips into one long MIDI clip which is a lot easier to deal with. When I do that I usually clone and archive the original track then do the Bounce to Clips in the clone (then delete everything EXCEPT the newly bounce clip). That's just as a precaution in case something weird happens when doing the bounce.
I just tossed a bunch of useful procedures and terms at you to manage your MIDI drums. You can google search them and or check out the manual to learn more about each. All are useful for managing your MIDI drum tracks though (and tracks in general... you can "Freeze" audio tracks as well to temporarily print effects onto the audio and remove thos eeffects from your computer resources which is useful if you have a lot of effects that are making your computer lag/choke).
BUT... unless you have a specific reason to bounce your MIDI drums, don't worry about it. EVen then just hitting the Freeze button will do the same thing except you can reverse it any time you like.
Cheers.