Coexistence of medullary sponge kidney and ulcerative colitis in the same patient: long-term follow-up

We describe a female patient with ulcerative colitis since the age of 17, who was accidentally diagnosed as having medullary sponge kidney 3 years after the establishment of diagnosis of inflammatory bowel disease. The diagnosis of renal disease was based on the typical appearance of both kidneys on abdominal ultrasound examination and on IV pyelography findings. All other well-known causes of medullary sponge kidney were excluded on the basis of the relevant laboratory investigation. So far, the patient experienced only one episode of urinary infection but no renal colic. Since the time of diagnosis of ulcerative colitis her renal function tests are perfectly normal. She is under maintenance treatment with mesalazine. The benign nature of the situation was explained to her. She was advised to drink at least one and a half litter of water daily, in order to reduce the risk of nephrolithiasis. The combination of the two disorders in our patient is probably the result of a chance. However, taking into account the potentially dangerous long-term results of medullary sponge kidney, we suggest that patients with ulcerative colitis must have a careful ultrasound examination of both kidneys at least at the time of diagnosis of the bowel disease, in order to exclude the possibility of medullary sponge kidney, as conservative measures could result in avoidance of potentially dangerous complications, such as renal stones and urinary infections.