We present a case of 62-year-old patient after cystectomy with intestinal neobladder due to bladder cancer, complicated by severe acid-balance disturbances. Due to poor clinical condition and metabolic acidosis patient temporarily required renal replacement therapy. After obtaining the stabile clinical status the patient was discharged with the recommendation of chronic oral treatment with the alkalizing agents and regular blood gas control. In the 6 month follow-up there were neither symptoms of uremia nor significant abnormalities in waterelectrolyte balance.