Rachel,
I bet you could cut apart the hem at the crotch and stitch double-sided velcro or snap fasteners to make it more convenient.

i just bought a bella band and i love it!!! it helps sooo much to support the bag and hide it too. it is a stretchy band ..sort of like a tube top or top of pantyhose but it looks like the bottom of a tank top if you wear a short top over it...just looks like you are wearing layers it allows you to wear your shorter tops again! and i wear it under my dresses cuz i hate feeling like the bag is just flopping around and i don't wanna buy granny panties to wear over it lol. it works great and comes in many colours..some have lace on the bottom too. it is actually a maternity item- i got mine at a maternity consignment store. brand new i think they are $30-40...they are sposed to help pregnant women who are just getting big so they can wear their old jeans still- so they can undo the fly and the bella band goes over top to keep everything flat and hold up the pants. they thought i was pregnant in the store...and it didn't help that i kept on touching my stomach to check my bag (a weird habit i have, and i do it all the time)...lol.

Nikki, I'm so glad you mentioned this because I was thinking about trying one out and wasn't sure if it would have the desired effect.

ooo i have more ideas and tips

#1...at american eagle they have bandeau tops for only $10...i am going to try some on and see if it will work kinda like a bella band...they probably won't last as long or support as much but they are nice breathable, stretchy cotton...and i think they are gathered at the front a bit so maybe you wouldn't be able to wear them over the pants to look like it's the bottom of a tank..but i plan on wearing it under dresses on hot days just to hide the bag and to support a little so it is not flopping around! i think this might just work! i'm going to buy some to actually wear as a top too lol..they are great layering pieces cuz i just bought these really loose tank tops that have huge arm holes deep neck lines and i need something to go under them...nice and cheap and that is the way i like it! haha. i thought about doing this with bandeau style bikini tops - you might get more support but i don't think the fabric would breathe and i get sweaty on my belly....i think it was shell who said you can spray some deoderant on the skin under the bag to help out though.
#2 i'm also looking for shorts and light pants for this hot weather that have drawstring waists. i have always had a problem buying pants because my bum is small and if i buy it big enough to fit my waist and hips, it's all baggy in the bum...now the problem is even worse cuz i need even more room to accomodate the bag...i look like im wearing a diaper when i try on pants a size up lol...so i am on the lookout for good ones that have drawstring waists. they seem to fit best because i can buy a small and then loosen up the waist they have some at american eagle but i haven't tried them on yet. if you see good ones for cheap let me know! bermuda length preferred!