So I assume you continued on to just fill in the new soil mix around the roots. Did you tamp the pot against whatever surface you were working on to settle the soil around the roots so as to avoid air pockets? If you're an experienced planter this probably goes without mentioning it. I've found that dieffenbachia is one of those pretty tough and forgiving plants. I've often rooted cuttings (even large ones) in a jar of water and once there are roots (they develop really big roots in water after a few weeks) I've planted them with no problems. Hopefully it's just transplant shock. If things don't work out, just cut if off somewhere on the stem and root it in water. Either way, you shouldn't wind up completely losing the plant. I seem to recall having your exact same experience at times with repotting some of these - as well as other plants.

How long were the roots exposed? Were you misting them and keeping them moist in some fashion while they were out of soil?

Thank you for your feedback, I did keep the roots moist throughout the whole procedure and I also did tap the pot too so at least now I know I did pretty much all I could have done and hopefully it is just shock!

take some string or tape.. and wind it around the leaves ... bundle it up ...

we are trying to create some support to hold the leaves up .... until the roots start pumping enough water to hold itself upright on its own ...

just leave the tape there.. until it falls off by itself... do no more harm ...

ill see if i can find a pic as an example.. ken

this was a hosta outdoors ... but same principal ...

As long as it has plenty of water, it should only be droopy for a couple/few days before you start to see improvement.