Snapshot A 70-year-old man with a history of type 2 diabetes, diverticulosis, and hemorrhoids presents to the emergency room after an episode of syncope in the setting of a bloody bowel movement. He had gone to the bathroom and saw bright red blood in his stool. After standing up, he felt lightheaded and had to sit down on the floor. He is accompanied by his family members. His blood pressure is 110/70 mmHg and his pulse is 80/min. He is scheduled for a colonoscopy. Introduction Overview lower gastrointestinal bleed results from bleeding from the colon or rectum Epidemiology incidence very common epidemiology elderly patients with comorbid conditions risk factors diverticulosis angiodysplasia ischemic colitis neoplasm inflammatory bowel disease infection login to view 2 more bullets hemorrhoids anal fissure Pathogenesis mechanism depends on the etiology Prognosis can be inconsequential or life-threatening Presentation Symptoms common symptoms rectal bleeding login to view 5 more bullets a fever may indicate infectious etiology painless bleeding may indicate angiodysplasia or diverticular bleeding abdominal pain may indicate ischemic colitis Physical exam inspection dehydration Imaging Radionuclide scan indications often performed before angiography as it is not invasive and a negative result negates a need for further invasive procedures high sensitivity Angiography indications hemodynamically unstable patients if colonoscopy does not reveal a bleeding site in hemodynamically stable patients can also be therapeutic Studies Serum labs complete blood count serum electrolytes coagulation studies Invasive studies colonoscopy/anoscopy/sigmoidoscopy indication login to view 4 more bullets Differential Upper gastrointestinal bleed key distinguishing factor source of bleeding from stomach or small intestine may also present as bright red blood if there is rapid hemorrhage Treatment Medical resuscitation modalities login to view 3 more bullets Surgical colonoscopy/anoscopy/sigmoidoscopy indication login to view 2 more bullets modalities login to view 3 more bullets angiography indication login to view 3 more bullets modalities login to view 2 more bullets surgical exploration indication login to view 2 more bullets Complications Death Shock