[Sciatica secondary to a presacral abscess as the first manifestation of Crohn's disease].

Presacral abscess is a rare musculoskeletal complication of Crohn's disease. The clinical picture is sometimes insidious and a delay in diagnosis may increase morbidity. Abdominal-pelvic computerized axial tomography (CAT) has proven to be very useful in the diagnosis of this entity, which usually requires surgical treatment. We present the case of a 22-year-old man who presented to hospital for colic-type abdominal pain of 6 months' evolution and intermittent episodes of joint pain. The patient also presented mechanical pain in the right gluteus muscle of two weeks' evolution irradiating to the posterior side of the muscle. Complementary investigations confirmed the suspected diagnosis of Crohn's disease and showed presacral abscess. Treatment was surgical.