From the link I posted above:
Diarrhea in Dogs: Don?t Let It Catch You Unprepared Rice, even though it’s bland, is very fermentable. Fermenting rice in the colon of a pet with diarrhea tends to increase gassiness. Also, rice tends to just zip right through the GI tract, exiting with the next bout of explosive diarrhea totally undigested. Because of its large surface area (when compared to kernels of rice), many pets do much better with pureed pumpkin or sweet potato. Even through a bout of diarrhea, it is readily absorbed.
I remember when Princess had colitis, I cooked her 98% fat free turkey from Trader Joe's & white rice. When she had her bowel movement, a lot of the rice came out undigested. @ 1st, I thought they were worm eggs & almost fainted! I had some green pumpkin (not sure of the name, but it starts w/K), so I baked it in the oven & mushed it together w/the turkey. Vet ok'ed this bland diet for her, he said tilapia will work too.
Glad she's back to her normal self, hope she'll continue to do well. If it's recurring, I would get her vet checked for possible giardia, needs to be ruled out (maybe that's why you have the met/ flagyl?).