What is the appropriate workup for streaks of blood on toilet paper (hematochezia)?

Workup for Streaks of Blood on Toilet Paper (Hematochezia)

All patients with rectal bleeding, including streaks of blood on toilet paper, should undergo anoscopy and flexible sigmoidoscopy at minimum to rule out significant pathology, with consideration for full colonoscopy based on risk factors and bleeding characteristics.

Initial Assessment

The workup for streaks of blood on toilet paper should follow a systematic approach:

Step 1: Distinguish True Hematochezia from Other Causes

• Determine if blood is truly from the rectum versus other sources (e.g., hemorrhoids) 1
• Note that normal-appearing stools with streaks of blood on toilet paper may represent bleeding hemorrhoids rather than true dysentery 1
• Assess blood characteristics:
  • Bright red blood on toilet paper is typical of hemorrhoidal bleeding 1
  • Darker blood or blood mixed within stool suggests a more proximal source 1

Step 2: Physical Examination

• Perform external anal examination to identify:
  • External hemorrhoids 1
  • Anal fissures (best seen with eversion of the anal canal by opposing traction with thumbs) 1
  • Skin tags, thrombosed external hemorrhoids, or rectal mucosal prolapse 1
  • Perianal abscess or anal fistula 1

Step 3: Anoscopy

• Anoscopy is essential for visualizing internal hemorrhoids, which are the most common cause of bright red bleeding on toilet paper 1
• Internal hemorrhoids are optimally visualized using an anoscope with adequate light source 1

Further Diagnostic Evaluation

Mandatory Testing

• Flexible sigmoidoscopy should be performed in all patients reporting rectal bleeding, even if hemorrhoids are identified 1
• This approach would identify approximately 95% of significant lesions in patients with hematochezia 2

Extended Evaluation Criteria

Complete colonic evaluation by colonoscopy or air-contrast barium enema is indicated when:

• Bleeding is atypical for hemorrhoids (e.g., dark blood or blood mixed in feces) 1
• No source is evident on anorectal examination 1
• Patient has significant risk factors for colorectal cancer 1
• Patient has guaiac-positive stools or anemia 1
• Patient reports blood mixed within stool (p=0.03), more frequent episodes of hematochezia per month (p=0.008), or shorter duration of bleeding before seeking medical evaluation (p=0.02) 2

Risk Stratification for Colonoscopy

Consider full colonoscopy based on:

• Age (especially ≥45 years) 2
• Family history of colorectal cancer 1
• Personal history of polyps 1
• Presence of anemia 1
• Guaiac-positive stools 1
• Bleeding characteristics inconsistent with hemorrhoids 1

Common Pitfalls to Avoid

• Do not assume hemorrhoids are the cause without proper examination - Other pathologies are often overlooked when hemorrhoids are simply assumed to be the cause 1
• Do not rely solely on patient descriptions of bleeding - Physician predictions are not reliable in evaluating hematochezia without direct examination 1
• Do not attribute fecal occult blood to hemorrhoids without colonic evaluation - Hemorrhoids alone do not cause positive stool guaiac tests 1
• Do not miss concurrent pathology - As many as 20% of patients with hemorrhoids have concomitant anal fissures 1
• Do not confuse rectal varices with hemorrhoids in patients with portal hypertension, as they require different management 1

Management Considerations

If hemorrhoids are confirmed as the source of bleeding:

• First-degree hemorrhoids (bleed but do not protrude) respond best to medical therapy 1
• The cornerstone of medical therapy is adequate intake of fiber and water 1
• Topical corticosteroids and analgesics may help manage perianal skin irritation 1
• Avoid prolonged use of potent corticosteroid preparations 1
• Consider toilet habit modification, as longer sitting times may correlate with hemorrhoidal grade 3

For hemorrhoids not responding to medical therapy, consider:

• Nonoperative techniques (injection sclerotherapy, rubber band ligation, etc.) for second and third-degree hemorrhoids 1