Rectal Bleeding

Ted Epperly

Rectal bleeding is a common problem encountered by primary care providers across the United States. Annually, approximately 3% of the general population will report seeing blood in the toilet bowl and roughly 12% to 20% will note blood on the toilet paper (1–3). The prevalence of rectal bleeding is significantly higher in persons aged 20 to 40 years (18.9%) than in those aged more than 40 years (11.3%) (2). Only 14% to 28% of patients with rectal bleeding consult their doctor for this problem (2,3).

Approach

The key issue for the primary care provider is to determine which patients need aggressive diagnostic evaluation and which patients can be reassured and followed over time. The diagnostic approach is based on history, physical examination, and risk factor assessment. The differential diagnosis of rectal bleeding is presented in Table 9.9.

History

A. Initial history. The history is an important tool for risk stratification. Important questions to ask: What is the color of blood passed? Is the bowel movement associated with pain? How long has the bleeding occurred? Is there blood on toilet tissue versus mixed with stool, or dripping into the toilet bowel? Have there been prior episodes? Is abdominal pain, constipation, diarrhea, medication use, or weight loss present? What medications do you take? The only historical questions that have evidence-based data to support benign versus serious pathology are the presence of constipation, diarrhea, age less than 50 years, and bleeding longer than 2 months (1,2) (Chapters 9.3 and 9.4). These findings are associated with more benign causes. An exception to this is in the pediatric age group where bleeding in children can represent hereditary and anatomic anomalies (4).

B. Other questions that can help discriminate serious from benign causes are a change in bowel habit to persistent loose stools for more than 1 month, absence of perianal symptoms in the presence of rectal bleedings, first time rectal bleeding, and the appearance of dark red blood (3). These are especially likely to be associated with more serious causes.

Physical examination

 Assess the patient’s weight, general condition, and vital signs. Orthostatic blood pressure changes with a drop of 10 mm Hg or an increase in heart rate of 10 beats/minute indicates a blood loss of at least 1,000 ml (20% of circulating blood volume) (5). It is important to perform an external anal inspection, (checking for external hemorrhoids, fissures), digital rectal examination (checking for a rectal mass, polyp or anal pain), abdominal examination (checking for tenderness or mass), and nasopharyngeal examination (checking for a bleeding source).

Testing

A. Anoscopy. The anoscope allows inspection for fissures, fistulas, bleeding and nonbleeding hemorrhoids, and rectal friability.

B. Rigid proctosigmoidoscopy has given way to flexible sigmoidoscopy; it visualizes well the distal 25 cm of the proctosigmoid area for neoplasia, friability, polyps, ulcers, or hemorrhoids. Rigid sigmoidoscopy has a sensitivity of 69% and specificity of 95% in determining the presence or absence of disease (1).

C. Flexible sigmoidoscopy is much better tolerated by the patient than rigid proctosigmoidoscopy. It visualizes the distal 60 to 70 cm of the colon and detects similar findings as rigid proctosigmoidoscopy with similar sensitivity and specificity.

D. Air contrast barium enema demonstrates polyps, masses, mucosal irregularities, diverticulae and inflammatory bowel disease with a sensitivity of 52% and a specificity of 98% (1). When used in combination with sigmoidoscopy, it has a sensitivity of 96% and specificity of 76% with a positive predictive value of 55% (1).

E. Stool guaiac testing. As a test for occult bleeding in determining serious pathology, the guaiac card has a sensitivity of 44% to 75% and a specificity of 85%. As a screening tool, it has received mixed blessings, being promoted by the American Cancer Society and National Cancer Institute, but with insufficient evidence to recommend for or against by the US Preventive Services Task Force.

F. Colonoscopy. The diagnostic procedure of choice to visualize the entire colon. It allows only one bowel preparation and has identification rates of 74% to 82% of lower GI bleeding sources (5). The sensitivity of this examination approaches 98%.

G. Nuclear scintigraphy. ^99mTechnetium-labeled red blood cells detects occult bleeding sources when the above-mentioned methods fail. Sensitivity ranges from 80% to 98% in the colon with specificity of 41% to 97% (5).

H. Mesenteric angiography uses a transfemoral placement to selectively evaluate the superior mesenteric, inferior mesenteric, and celiac axis. The sensitivity is 40% to 86% with a complication rate of 2% (5). Treatment interventions include arterial infusion of vasopressin and embolization with coil springs or gel foam.

I. Enteroscopy. Small bowel enteroscopy uses a special enteroscope or pediatric colonoscope. This scope is passed orally and has a diagnostic yield of 25% (5).

Diagnostic assessment

The answers provided in the patient’s history and physical examination are important to risk stratify this common problem. If a workup is believed necessary to deal with diagnostic uncertainty, then the entire colon should be visualized. This approach should consist of a digital rectal examination, anoscopy, rigid or flexible sigmoidoscopy, and the use of air contrast barium enema as deemed necessary. Alternatively, exploration by colonoscopy can be used, based on the provider’s discretion. The latter makes most sense as two bowel preparations can be reduced to one with enhanced patient comfort. Further workup, including nuclear scintigraphy, mesenteric angiography, enteroscopy, and referral to a surgeon or a gastroenterologist, depends on the clinical situation and seriousness of the bleed encountered. Serious pathology occurs in approximately 25% of rectal bleeding patients with 6.5% to 10% having cancer, 13% to 25% having polyps, and 4% to 11% having inflammatory bowel disease (1,2). Ten year follow-up of patients with benign anorectal disease or no evident cause of bleeding found no difference in the incidence of cancer compared with similarly aged cohort in the general population (1).

References

1. Helfant M, Marton KI, Zimmer-Gembeck MJ, Sax HC. History of visible rectal bleeding in a primary care population: initial assessment and 10-year follow-up. JAMA 1997;277(1):44–48.

2. Talley NJ, Jones M. Self reported rectal bleeding in a United States community: prevalence, risk factors, and health care seeking. Am J Gastroenterol 1998;93:
2179–2183.

3. Thompson M, Prytherah D. Rectal bleeding: when is it right to refer. Practitioner 1996;240:198–200.

4. Colletti RB, Compton CC. Weekly clinicopathological exercises: case 7-1997. A 14-year-old girl with recurrent painless rectal bleeding. N Engl J Med 1997;336(9):
641–648.

5. Vernava AM, Moore BA, Longo WE, Johnson FE. Lower gastrointestinal bleeding. Dis Colon Rectum 1997;40:846–858.

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Book Source Details

• Book Title: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter
• Author(s): Robert B. Taylor (editor)
• Year of Publication: 2000
• Copyright Details: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, Copyright © 2000 Lippincott Williams & Wilkins.

Other Book Chapters Related to Gastrointestinal bleeding

Read excerpts from these other book chapters related to Gastrointestinal bleeding:

Copyright Details: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, Copyright © 2008 Williams & Wilkins.

More About Causes of Gastrointestinal bleeding

• Back to symptom: Gastrointestinal bleeding: Introduction (review 199 causes)
• Next Book Extract About Gastrointestinal bleeding: Gastrointestinal Bleeding (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)
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More About This Book: Title: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter Authors: Robert B. Taylor (editor) Publisher: Lippincott Williams & Wilkins Copyright: 2000 ISBN: 0-78172-094-X

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