GI emergencies: rapid therapeutic responses for older patients. 
Comorbid conditions and decreased physiologic reserves make persons age 65 and older particularly vulnerable to the adverse consequences of acute blood loss.  Thus, gastrointestinal bleeding in this population presents an urgent clinical challenge.  Treatment of such emergencies may be the preview of the gastroenterologist, but the primary care physician can play a key role in the preliminary diagnosis and management, timely referral for emergency intervention, and follow-up care.  Because of age-related changes, including decreased cardiovascular reserve and a higher risk of hemorrhage, any evidence of GI bleeding in an older patient demands diligent intervention.