Inclusion Criteria:  Patient admitted to Methodist Dallas Medical Center Age greater than 18 years Patient evaluated by gastroenterology consult service during admission Hospitalization with diagnosis of "hematochezia", "acute gastrointestinal bleeding", "acute blood loss anemia", or "anemia" Endorsed or witnessed episode of painless hematochezia Patients exhibiting hemodynamic stability (heart rate <110; systolic blood pressure >90) after initial evaluation and resuscitation by admitting/emergency room physicians  Exclusion Criteria:  Age less than 18 years Persistent hypotension despite initial intravenous fluid resuscitation or fever Bowel preparation started 24 hours after initial presentation Documented symptoms of dysphagia or odynophagia Signs or symptoms suggestive of gastrointestinal obstruction (or ileus) on initial presentation (e.g., abdominal pain, nausea and/or vomiting) Inability to complete bowel preparation Personal history of inflammatory bowel disease or cirrhosis History of immunosuppression (e.g., AIDS, immunosuppressive medication) Personal history of colon cancer Prior gastric bypass, small bowel, or colonic resection Stool culture positive for tested organisms to include Clostridium difficile