Ok, I just got an email from my friend about his cat who had a similar problem and this is what he did.

CVS Natural Lax powder ~ has psyllium husk ~ teaspoon powder & water ~ Use oral syringe about 3 or 4 ML ~ squirt in mouth

He also gave her lactulose from his vet as Candace suggested. So it wasn't bran that he gave her but he was on the right track and that was a couple of years ago and his cat is doing great. Perhaps suggest this to your vet before you have Kacey PTS. I know that you say Kacey is gassy so this may not apply but it's worth a chat w/your vet about it. Good luck, sweetie. I know how troubling this is and you want Kacey to be at peace.