Management of Acute Lower Gastrointestinal Bleeding

Initial Assessment and Risk Stratification

Patients with lower GI bleeding should be categorized into four groups: minor bleeding, chronic intermittent bleeding, severe life-threatening bleeding, or continual active bleeding, according to the American Gastroenterological Association 1
The BLEED classification system can identify patients at high risk of adverse outcomes, including those with ongoing bleeding, low systolic blood pressure, elevated prothrombin time, erratic mental status, and unstable comorbid disease, as recommended by the European Society of Gastrointestinal Endoscopy 3, 4
Risk factors for severe lower GI bleeding include initial heart rate >100/min, systolic blood pressure <115 mmHg, syncope, nontender abdominal examination, bleeding per rectum during first 4 hours of evaluation, aspirin use, and more than two active comorbid conditions, as identified by the American College of Gastroenterology 3, 4

Immediate resuscitation with intravenous fluids should be initiated for hemodynamically unstable patients, as recommended by the American College of Surgeons 1
Correct coagulopathy or thrombocytopenia with fresh frozen plasma or platelets as needed, according to the American Association of Blood Banks 1

For patients with severe hematochezia and hypovolemia, consider an upper GI source, which accounts for 10-15% of such cases, as noted by the American Gastroenterological Association 5, 1
Perform upper endoscopy early in patients with risk factors for peptic ulcer, portal hypertension, or angiodysplasia, as recommended by the European Society of Gastrointestinal Endoscopy 5, 6

Colonoscopy is the diagnostic procedure of choice for acute lower GI bleeding with a diagnostic accuracy of 72-86%, according to the American Society for Gastrointestinal Endoscopy 5, 1
Rapid bowel cleansing prior to colonoscopy improves visualization and diagnostic yield, as recommended by the American College of Gastroenterology 5, 1

Radionuclide imaging with [99Tcm] pertechnetate-labeled red blood cell scanning can detect bleeding at rates of 0.1-0.5 mL/min and is useful for episodic bleeding, as noted by the Society of Nuclear Medicine and Molecular Imaging 1
A positive red blood cell scan should be followed by urgent angiography within 1 hour for potential therapeutic intervention, according to the American College of Radiology 1

Consider angiography with embolization for patients with ongoing bleeding not amenable to endoscopic therapy, as recommended by the Society of Interventional Radiology 7, 8
Intra-arterial vasopressin infusion can control bleeding in up to 91% of patients with diverticular disease or angiodysplasia, though bleeding recurs in up to 50% after cessation, according to the American College of Gastroenterology 8

Reserve surgery for patients with persistent hemodynamic instability despite resuscitation, transfusion requirements >6 units, or severe recurrent bleeding, as recommended by the American College of Surgeons 7
Accurate preoperative localization of the bleeding site is essential for successful segmental resection, according to the American Society of Colon and Rectal Surgeons 7
Blind segmental resection or emergency subtotal colectomy without localization are associated with high rebleeding rates (up to 33%) and mortality (33-57%), as noted by the European Society of Coloproctology 7

Failing to consider an upper GI source in patients with severe hematochezia can lead to delayed diagnosis and treatment, as warned by the American Gastroenterological Association 1, 5
Delaying colonoscopy may reduce the ability to identify stigmata of recent hemorrhage, according to the American Society for Gastrointestinal Endoscopy 1
Performing blind segmental resection without adequate localization of the bleeding source leads to high rebleeding and mortality rates, as cautioned by the American College of Surgeons 7