Just make sure you keep taking your probiotics while in remission.
I take probiotics (primadophilus reuteri made by natures way, 5 billion CFU, which is a recommended amount to take), I don't know if there necessarily is a limit of how much one can take (I doubt it would do any harm) it's just a matter of cost wise and waste wise, if you're taking enough of what's needed, at least 5 billion I believe (it could even be less) then taking any more would be expensive and wastefull I would imagine...
as far as fibre supplements go, yes, it's very beneficial, my GI told me to take them daily for the rest of my life, always start with a small amount and only increase if necessary and very slowly...they can cause extra gas and bloating which is very normal, just stick with it daily and it will go away...for me it's bulked my stools up nicely, no constipation as with fibre supplements it aids either D or C, I go less frequently with larger deposits rather then frequently with little ones, no more mucus either...I use prodiem stool bulker, it's similar to metamucil tabs....always drink lots of water with fibre supplements...taking the supplements has also made it easy to tolerate fibreous foods, I don't get gassy or bloated after eating fibre foods.
My bum is broken....there's a big crack down the middle of it! LOL :)