Has anyone had problems with kidney stones post colectomy & j-pouch surgery?

I had a colectomy performed in Manchester, England following toxic UC in 1997. Then s-pouch surgery by Dr. Fazio at the cleveland clinic in 1998. All had been going well until 2010 when I discovered a large kidney stone (1/3 calcium oxalate 2/3 uric acid) that required lithotripsy to remove it. 1 year later another stone in exactly the same place requiring ESWT. I am concerned over how quickly the 2nd stone formed (2.5 cm).
Has anyone else had problems with kidney stones & how have you managed it?
I am trying to drink 3L of water a day, use fiber (flax seed & metamucil), decrease oxalate rich vegetables & eat less meat, potassium citrate to increase urine pH.
Any other thoughts?
Thanks

I haven't had your surgery, but i get them secondary to my UC. They suggested drinking lots of lemonade. I also take potassium citrate pills. They have helped a lot. I was also put on hydrochlorothiazide to push the water through. Seems to be working. After 1 emergency basket removal and one lithotripsy, I don't want to ever go through that mess again.

Thanks for your feedback.