What should be done for a patient experiencing rectal bleeding?

Management of Rectal Bleeding

For a patient with rectal bleeding, immediately assess hemodynamic stability and perform digital rectal examination, then proceed with ano-proctoscopy or flexible sigmoidoscopy as the first-line diagnostic tool, followed by colonoscopy within 24 hours if high-risk features are present. 1, 2, 3

Initial Assessment and Hemodynamic Stabilization

Check vital signs, hemoglobin/hematocrit, and coagulation parameters immediately to determine bleeding severity. 4, 2, 3

• Calculate the shock index (heart rate divided by systolic blood pressure); a value >1 indicates hemodynamic instability requiring urgent intervention 3
• Perform blood typing and cross-matching if severe bleeding is present 4, 2
• Apply the Oakland score for risk stratification: assign points based on age, previous lower GI bleeding admission, blood on digital rectal exam, heart rate, systolic blood pressure, and hemoglobin level 3
• A score >8 indicates major bleeding requiring hospital admission 3

Resuscitation Protocol

For hemodynamically unstable patients, initiate immediate IV fluid resuscitation and maintain hemoglobin >7 g/dL during the resuscitation phase. 4, 2, 3

• Maintain mean arterial pressure >65 mmHg while avoiding fluid overload, as excessive volume expansion can exacerbate portal pressure and increase rebleeding risk 4
• Correct coagulopathy and optimize management of antiplatelet agents and anticoagulants through a multidisciplinary approach 4

Diagnostic Algorithm

For Hemodynamically Stable Patients

Perform digital rectal examination and ano-proctoscopy or flexible sigmoidoscopy as the first-line diagnostic approach. 4, 1, 2, 3

• Digital rectal examination identifies common anorectal causes such as hemorrhoids, anal fissures, or palpable rectal masses (present in 36% of cancer patients) 3, 5
• Examine the rectum with retroflexion (J-maneuver) to evaluate hemorrhoidal disease and low rectal pathology 3
• Proceed to colonoscopy within 24 hours after adequate bowel preparation, which has a diagnostic yield of 42-90% 3

A critical pitfall: Do not assume a lower GI source without excluding upper GI bleeding, as 8-15% of patients with rectal bleeding have an upper gastrointestinal source. 4, 2

For Hemodynamically Unstable Patients

Perform CT angiography as the first-line investigation before endoscopy. 2, 3

• CT angiography has a sensitivity of 79-95% and specificity of 95-100% for detecting active bleeding without requiring bowel preparation 2
• If CT angiography does not identify the source, perform upper endoscopy immediately to rule out an upper GI source 2
• Avoid delaying CT angiography by attempting colonoscopy first in unstable patients 2, 3

High-Risk Features Requiring Urgent Intervention

Perform urgent colonoscopy (plus upper endoscopy) within 24 hours if any of the following are present: 4, 1

• Evidence of ongoing bleeding 4, 1
• Hemodynamic instability (hemoglobin drop ≥1.5 g/dL or need for blood transfusion) 4
• Risk factors for colorectal cancer (the risk ranges from 2.4-11% in patients with rectal bleeding) 4, 2
• Suspicion of a concomitant more proximal source of bleeding 4, 1

When to Perform Full Colonoscopy

Complete colonoscopy is mandatory if the patient has risk factors for colorectal cancer or suspected proximal bleeding source. 4, 1, 2

• Approximately 6% of patients presenting with lower GI bleeding have underlying bowel cancer 3
• Rectal bleeding associated with change in bowel habit increases cancer prevalence to 9.2% 5
• Rectal bleeding without perianal symptoms increases cancer prevalence to 11.1% 5

Management of Specific Causes

If Anorectal Varices Are Identified

Use endoscopic variceal ligation, band ligation, sclerotherapy, or EUS-guided glue injection as first-line treatment to arrest bleeding. 4, 1

Pharmacological Management for Varices

• Administer vasoactive drugs (terlipressin or octreotide) to reduce splanchnic blood flow and portal pressure 4, 1
• Provide a short course of prophylactic antibiotics 4, 1
• Initiate non-selective beta-adrenergic blockers for prevention of first and recurrent variceal bleeding (temporarily suspend during acute bleeding) 4, 1

Advanced Interventions for Refractory Variceal Bleeding

Use a step-up approach: medical treatment → endoscopic procedures → radiological interventions → surgical procedures. 4, 1

• Consider embolization via interventional radiological techniques for short-term bleeding control 4, 1
• Use percutaneous transjugular intrahepatic portosystemic shunt (TIPS) for severe portal hypertension to decompress the portal venous system and reduce rebleeding risk, if not contraindicated 4, 1
• Endorectal placement of a compression tube can serve as a bridging maneuver for stabilization or transfer to a tertiary hospital 4, 1

If Radiation-Induced Rectal Bleeding Is Identified

Optimize bowel function and stool consistency first, which may reduce bleeding without intervention. 4

• If bleeding does not affect quality of life (no staining of clothes, no anemia, no interference with daily activities), reassure and observe 4
• If bleeding affects quality of life, stop or reduce anticoagulants if possible 4
• For severe bleeding, initiate sucralfate enemas (2g suspension in 30-50 ml tap water, administered twice daily via soft Foley catheter, retained as long as possible) 4
• Sucralfate enemas are more effective than corticosteroid enemas for radiation-induced bleeding 4

A critical warning: Argon plasma coagulation has a serious complication rate of 7-26% in radiation-induced rectal bleeding due to deep ulceration, bleeding, fistulation, perforation, and stricture formation in chronically ischemic tissues. 4

Common Pitfalls to Avoid

• Do not discharge patients with an Oakland score >8 without hospital admission and investigation 3
• Do not rely on gastric lavage in suspected upper GI bleeding, as it does not provide reliable diagnosis and may cause complications 2
• Do not delay complete colonoscopy in patients over 50 years or those with alarm features, as over 96% of patients with rectal bleeding do not have cancer, but the 3.4% who do require timely diagnosis 5
• Do not assume hemorrhoids are the cause without proper visualization, as distinguishing hemorrhoids from anorectal varices can be difficult, especially with massive bleeding 4