My sympathies to your husband. I had my first kidney stone 1 week before I was to leave for a land tour of Macchu Pichu. Actually, the kidney stone saved my life because while the stone was in my left kidney, they discovered a renal cell carcinoma in my right kidney. I later had my right kidney removed.
In any case, the doctor wrote a note that it was unadvisable to travel. My travel insurance covered all costs, but it took time and filling out all the paperwork was a pain.