Gastrointestinal disorders may affect other organ systems; knowledge of these overlapping conditions is essential to the practicing urologist. The genitourinary manifestations of inflammatory and neoplastic disorders of the bowel will be extensively reviewed. In addition, the surgical treatment morbidity of these gastrointestinal disorders will be considered and the pathophysiology explored. Lastly, the metabolic consequences of gastrointestinal diseases in relation to nephrolithiasis will be reviewed.