Dear Gina,
For sure I'd consult a nephrologist and a gastroenterologist. In fact, I'd make sure they talk to each other about any findings or treatments.
I have ulcerative colitis, diagnosed after my donation, and my gastroenterologist is always cautious about medications that have any possible nephrotoxic effect. In fact, when I have a colonoscopy he's selective about the preparation medications. I also have labs every 6 months.
Don't dread the medical system but do be your own advocate!
Love, elephant
My eGFR has been 48-54 for four years since donation, but this has not been considered to be particularly unusual since I have only one kidney. A steady declining trend is different than if it is stable.