I am really saddened by MOUSE's story -- it feels like good people really can't be happy in this imperfect world of ours. MOUSE, you and your partner sound like good people. I wished I could say there was a safe way to eliminate uric acid that would let you just continue your lovely after-work pee-drinking sessions; your line about this kink both of you enjoyed having been taken away from you did really sound sad. But I can't tell you any such thing, and what Dan wrote in his advice is, as far as I can tell (I've done some search of my own), factually accurate.

All I can offer is my solidarity. I understand it is hard to have to give up something that is yours, that brings the two of you together, and feels kinky and adventurous. Especially since, under the circumstances, you, MOUSE, would probably experience some guilt -- which is never a good thing to feel with respect to a loved one. And I can imagine your partner's feelings about the incident must also be complicated and ambivalent.

Please accept my sympathy. There's at least one person out there hoping that this incident will not bring too much unhappiness into your life, and your partner's. I sincerely do.

All the best,

This may be too late to be of any help, but I have a suggestion for MOUSE and sig-o for a more or less low-risk way to indulge themselves:
pee (in the usual receptacle), then drink a lot of water. You'll need to pee again in short order, but there will be very little uric acid in it.