What is the workup for melena (black, tarry stools) causing anemia?

From the Guidelines

The workup for melena causing anemia should begin with a thorough history and physical examination, followed by laboratory tests including complete blood count, iron studies, and coagulation profile, and upper endoscopy (EGD) should be performed within 24 hours as melena typically indicates upper gastrointestinal bleeding. Initial management includes hemodynamic stabilization with intravenous fluids and blood transfusions if hemoglobin is below 7 g/dL or if the patient is symptomatic, as recommended by the American Society of Anesthesiologists 1.

The diagnostic approach should prioritize identifying the source of bleeding, with upper endoscopy being the most appropriate initial test, as it allows for direct visualization of the upper gastrointestinal tract and potential therapeutic interventions 1. If the EGD is negative, colonoscopy should follow to evaluate for right-sided colonic sources. For ongoing bleeding with negative endoscopic findings, consider video capsule endoscopy, CT angiography, or tagged red blood cell scan.

Specific treatments depend on the identified cause, such as peptic ulcers, which may require proton pump inhibitors (e.g., pantoprazole 40mg IV twice daily initially, then oral therapy), H. pylori eradication if present, or endoscopic interventions like clipping or cautery for active bleeding 1. Variceal bleeding requires band ligation and possibly octreotide (50mcg IV bolus followed by 50mcg/hour infusion). Iron supplementation (ferrous sulfate 325mg three times daily) should be initiated to correct anemia once bleeding is controlled, as iron deficiency anemia in men and post-menopausal women is most commonly caused by gastrointestinal blood loss or malabsorption 1.

Key considerations in the management of melena causing anemia include:

• Hemodynamic stabilization and blood transfusions as needed
• Prompt upper endoscopy to identify and potentially treat the source of bleeding
• Colonoscopy if upper endoscopy is negative
• Consideration of video capsule endoscopy, CT angiography, or tagged red blood cell scan for ongoing bleeding with negative endoscopic findings
• Treatment of the underlying cause, such as peptic ulcers or variceal bleeding
• Iron supplementation to correct anemia once bleeding is controlled.

From the Research

Workup for Melena Causing Anemia

• The workup for melena causing anemia typically involves a combination of upper and lower endoscopy to identify the source of bleeding 2.
• A study found that same-day upper and lower endoscopy in patients with melena or anemia suspected to be caused by gastrointestinal bleeding can help identify potential bleeding sources in the upper and lower gastrointestinal tract 2.
• The study also found that a potential bleeding source in the upper gastrointestinal tract could have been missed in 25% of patients if only colonoscopy had been performed, and a potential bleeding source in the lower gastrointestinal tract could have been missed in 26% of patients if only esophagogastroduodenoscopy had been performed 2.

Role of Capsule Endoscopy

• Capsule endoscopy can be useful in identifying the source of bleeding in patients with melena or iron deficiency anemia, especially when upper and lower endoscopy are negative 3.
• A study found that earlier use of capsule endoscopy in inpatients with melena or severe iron deficiency anemia reduced the need for colonoscopy and shortened hospital stay 3.
• Capsule endoscopy can also be useful in identifying small bowel findings, which can be a source of bleeding in patients with melena 3, 4.

Examination Strategies in Children

• In children, the upper gastrointestinal tract is the most common source of bleeding in patients with melena 4.
• Esophagogastroduodenoscopy is the primary endoscopic method of choice for evaluating melena in children, and small bowel capsule endoscopy may be useful in identifying the bleeding source in children without upper gastrointestinal lesions 4.

Management of Anemia

• Anemia is a common worldwide problem that can be associated with nonspecific complaints, and the initial focus for evaluation is to determine whether the problem is acute or chronic 5.
• The severity of anemia impacts clinical outcomes, particularly in critically ill patients, and a restrictive transfusion strategy is associated with better outcomes than a more liberal transfusion strategy 5.
• The management of haematemesis and melaena typically involves endoscopic therapy, such as injection with dilute adrenaline or application of heat using the heater probe, and operative surgery may be required if bleeding recurs 6.