What are the causes of acute rectal bleeding (hematochezia)?

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Last updated: April 15, 2025View editorial policy

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From the Guidelines

Acute rectal bleeding should be evaluated promptly by a healthcare provider, especially if it's severe or accompanied by symptoms like dizziness, rapid heart rate, or abdominal pain. The management of acute rectal bleeding depends on the severity of the bleeding and the underlying cause. For mild cases, conservative management includes increasing fluid intake, avoiding straining during bowel movements, and using over-the-counter medications like hydrocortisone cream for hemorrhoids 1. If hemorrhoids are suspected, a sitz bath (warm water soaking of the anal area) for 10-15 minutes several times daily can provide relief. Patients should avoid alcohol, spicy foods, and NSAIDs which can exacerbate bleeding.

Diagnostic Approach

For moderate to severe bleeding, a more thorough diagnostic approach is necessary. This may include blood tests, endoscopy, and imaging studies to determine the underlying cause of the bleeding 1. The urgency of evaluation depends on the patient's age, bleeding severity, and associated symptoms, with older patients and those with significant bleeding requiring more urgent assessment.

Role of Endoscopy

Endoscopy plays a crucial role in the diagnosis and management of acute rectal bleeding. It can help identify the source of bleeding and allow for therapeutic interventions such as endoscopic variceal ligation or sclerotherapy 1. In patients with suspected bleeding anorectal varices, endoscopy is recommended as the first-line diagnostic tool, followed by EUS +/- color Doppler evaluation if necessary 1.

Imaging Investigations

Imaging investigations such as contrast-enhanced CT-scan or MRI angiography may be useful in patients with bleeding anorectal varices who have failed detection of bleeding site at endoscopy and EUS, or whenever EUS is not available 1. These imaging modalities can help identify the source of bleeding and rule out other causes of lower gastrointestinal bleeding.

Management of Severe Bleeding

Severe bleeding requires immediate medical attention and may necessitate hospitalization for close monitoring and management. In cases of severe bleeding, blood transfusions may be necessary to stabilize the patient, and surgical intervention may be required if endoscopic and medical management fail to control the bleeding 1.

In summary, the management of acute rectal bleeding requires a prompt and thorough evaluation to determine the underlying cause and severity of the bleeding. A combination of conservative management, endoscopy, imaging studies, and surgical intervention may be necessary to control the bleeding and prevent complications. The most important consideration is to prioritize the patient's morbidity, mortality, and quality of life, and to take a proactive approach to managing severe bleeding.

From the Research

Definition and Prevalence of Acute Rectal Bleeding

  • Acute rectal bleeding accounts for approximately 1 out of every 1000 United States emergency department visits annually 2.
  • The causes of rectal bleeding are broad, and can range from the benign to the life-threatening 2.

Management and Resource Utilization

  • The management of patients with per rectal (PR) bleeding is resource intensive 3.
  • A retrospective analysis of patients with PR bleeding found that 19% of patients required blood transfusion, 13% had computed tomography mesenteric angiogram, 4% had embolization, and 13% underwent diagnostic and/or therapeutic colonoscopy 3.
  • Patients referred from other facilities were more comorbid, more likely to be on antiplatelet or anticoagulant, with a higher rate of embolization, more packed cell transfusions, and longer length of stay 3.

Resuscitation Strategies

  • In cases of trauma, uncontrolled bleeding is the leading cause of preventable death, and Acute Coagulopathy of Trauma is present in 30% of patients on admission to hospital 4.
  • Damage Control Resuscitation aims to give a hemostatic resuscitation and avoid deaths caused by bleeding, considering control of bleeding with damage control surgery or interventional procedures, early transfusion of all blood products, permissive hypotension, and limited use of crystalloids 4.
  • Early transfusion of all blood products, with a ratio close to 1:1, may be associated with lower mortality and less requirements of total transfusions in trauma patients at risk of massive bleeding and massive transfusion 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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