[Left-sided hydronephrosis as the first sign of Crohn disease]

A previously well 29-year-old man was referred to the emergency department because of acute left lower abdominal pain without intestinal symptoms. Physical examination was unremarkable except for moderate suprapubic pain on pressure.

There was evidence of a urinary infection. Erythrocyte sedimentation rate was increased (48 mm/h) and C-reactive protein elevated to 42 mg/l. There was mild leucocytosis (10000/microliter). Abdominal sonography revealed an enlarged left renal pelvis with hydroureter and possible prevesical stone, findings confirmed at excretion urography.

He was discharged with the suspected diagnosis of ureteric stone and given co-trimoxazole, diclofenac and hyoscine butylbromide. After discontinuing medication the same symptoms developed two weeks later. Cystoscopy and retrograde pyelography were unremarkable and it was assumed the stone had been passed. The patient was again discharged on the above medication. When it was discontinued the same symptoms recurred and he was again admitted. Computed tomography, selective small-intestine radiology, coloscopy and biopsy indicated Crohn's disease with hydronephrosis as complication. Treatment trial with prednisone and mesalazine brought about only transient improvement so that an ileocaecal resection and ureterolysis were performed. The patient has since been free of symptoms.

If there are urological complications, chronic inflammatory intestinal disease should be included in the differential diagnosis even in the absence of any intestinal symptoms.