A 26-year-old male college student presented with 1 week of constant, right lower quadrant, throbbing abdominal pain that was worse after eating and accompanied by bilious emesis. He had experienced similar, albeit less severe and self-limited, episodes of abdominal pain during the preceding 6 months. He denied fevers or chills but had lost 4.5 kg (10 lbs) in the past 6 months. During the same time period, he was treated twice with antibiotics for urinary tract infections (UTIs) after reporting symptoms of dysuria and noting "bubbles" in his urine. A urine culture was never obtained. Urinary tract infections are uncommon in men because of the longer length of the male urethra, antibacterial properties of prostatic fluid, and less frequent periurethral colonization in men. The incidence in men younger than 50 years is approximately 5 to 8 per 10,000 per year. The incidence of UTIs in men increases with age, and the lifetime prevalence is estimated at 13,000 to 14,000 per 100,000 adult men.1 Although most community-acquired UTIs in women can be treated empirically with antibiotics without the need for a urine culture, a urine culture should always be obtained when a male patient presents with a suspected UTI. Simple UTIs (eg, cystitis in women) can be treated with 3 days of antibiotics 2 ; however, UTIs in men are considered "complicated" by definition and warrant at least 7 days of antibiotic therapy. Dysuria is the most frequent presenting symptom of UTIs in both men and women. 1,3,4 Most UTIs are caused by gram-negative organisms from the colon that colonize the periurethral skin. E coli is the most common cause of UTIs in both sexes.On examination, the patient appeared pale and cachectic. Cervical, axillary, and inguinal lymph nodes were not palpable. His abdomen was scaphoid with marked right lower quadrant tenderness without rigidity, guarding, or rebound tenderness. An ill-defined mass was palpable in the right lower quadrant. There was no tenderness in the costovertebral angle. On auscultation, bowel sounds were normoactive. Laboratory studies yielded the following results (reference ranges provided parenthetically): hemoglobin concentration, 11.9 g/dL (13.5-17.5 g/dL); mean corpuscular volume, 78.3 fL (81.2-95.1 fL); white blood cell count, 15.9 × 10 9 /L (3.5-10.5 × 10 9 /L) with 85% neutrophils; and creatinine level, 1.1 mg/dL (0.9-1.4 mg/dL). Urinalysis revealed 21 to 30 white blood cells per high-powered field, 3 to 10 red blood cells per high-powered field, no casts, and numerous bacteria. A clean-catch, midstream urine specimen showed no bacterial growth. Urinary tract infections in men, especially if recurrent, warrant a search for an underlying structural abnormality, such as an enlarged prostate, colovesical fistulas associated with colonic malignancy or inflammatory bowel disease, and congenital malformations of the urogenital tract. Instrumentation of the urinary tract (eg, during a cystoscopy or catheterization) can result in UTIs in both men and women. Conditions that suppress immune function...