From the Guidelines
A digital rectal examination (DRE) is a crucial initial diagnostic tool for evaluating gastrointestinal (GI) bleeding, as it helps identify the source and severity of bleeding, and guides further diagnostic workup. The DRE can detect active bleeding, determine the color of stool, and assess for masses, hemorrhoids, anal fissures, or other rectal pathologies that might cause bleeding 1. According to the WSES-AAST guidelines, a complete physical examination, including a digital rectal examination, is recommended to rule out other causes of lower gastrointestinal bleeding in patients with suspected bleeding anorectal varices 1.
Key Points to Consider
- The DRE is a quick and simple procedure that requires no special equipment and can be performed at the bedside, providing immediate information to guide further diagnostic workup.
- The examination can detect occult blood that isn't visible to the naked eye and determine the color of stool, which helps identify the potential source of bleeding.
- Black, tarry stool (melena) suggests upper GI bleeding, while bright red blood typically indicates lower GI bleeding, particularly from the rectum or distal colon.
- The DRE is particularly useful in patients with suspected anorectal varices, as it can help rule out other causes of lower GI bleeding and guide the choice of subsequent diagnostic tests such as endoscopy, colonoscopy, or radiographic studies 1.
Diagnostic Approach
- In patients with suspected GI bleeding, a DRE should be performed early in the evaluation to help determine the urgency of additional interventions and direct the choice of subsequent diagnostic tests.
- The WSES-AAST guidelines suggest the use of ano-proctoscopy or flexible sigmoidoscopy as the first-line diagnostic tool in patients with suspected bleeding anorectal varices 1.
- In patients with high-risk features or evidence of ongoing bleeding, an urgent colonoscopy within 24 hours of presentation is recommended 1.
From the Research
Usefulness of Rectal Exam in Diagnosing GI Bleeds
- A digital rectal examination (DRE) is a valuable tool in the diagnosis and management of gastrointestinal (GI) bleeding, as it can help identify the source and severity of bleeding 2.
- The DRE can reduce hospital admissions, endoscopies, and medical therapy in patients with acute GI bleeding by providing clinicians with important information to guide management decisions 2.
- In patients with upper GI bleeding, a DRE may not be as useful in localizing the source of bleeding, as the bleeding may be proximal to the ligament of Treitz 3, 4.
- However, in patients with lower GI bleeding, a DRE can be useful in identifying the source of bleeding, such as hemorrhoids, rectal ulcers, or colon cancer 5.
- Other diagnostic modalities, such as colonoscopy, nuclear scintigraphy, conventional angiography, video capsule endoscopy, and computed tomography (CT) angiography, may also be used to evaluate patients with GI bleeding, depending on the available expertise and resources 6.
Diagnostic Yield of Rectal Exam
- A study found that colonoscopy had a high diagnostic yield in patients with rectal bleeding, with abnormal findings in 84% of patients 5.
- The most common diagnoses in patients with rectal bleeding were ulcerative colitis, colorectal carcinoma, and non-specific colitis 5.
- A DRE can provide important information about the presence and characteristics of blood in the rectum, which can help guide further diagnostic testing and management 2.
Clinical Management Decision
- The use of DRE in patients with acute GI bleeding can assist clinicians with clinical management decisions, including the decision to admit to hospital, start medical therapy, or perform endoscopy 2.
- A study found that patients who had a DRE were less likely to be admitted to hospital, started on medical therapy, or undergo endoscopy compared to patients who did not have a DRE 2.