I have been able to tolerate rice.  Recently, I added rice cereal to my diet.  I ended up having tons of flares and didn't make the connection at first.  Matia said it was common to tolerate rice but not be able to tolerate it in various processed forms.  I have eaten only potates for the last few days and my bladder has felt so much better.  Tomorrow, I am going to try regular rice again.  If you have numerous flares, I would recommend trying to eat one grain for a few days before adding another one into your diet.