Indications and Guidelines for Colonoscopy

Indications for Colonoscopy

• The American Gastroenterological Association recommends that patients with occult gastrointestinal blood loss and iron deficiency anemia with negative upper endoscopy should undergo colonoscopy to identify intestinal bleeding lesions 3, 4
• Patients presenting with major lower gastrointestinal bleeding should be admitted for colonoscopy on the next available list, as recommended by the British Society of Gastroenterology 5
• The British Society of Gastroenterology suggests that patients with minor self-terminating bleeding (Oakland score ≤8 points) without other indications for hospital admission can be discharged for urgent outpatient colonoscopy 5
• Patients with rectal bleeding who are over 50 years old should undergo colonoscopy within 2 weeks due to 6% risk of underlying bowel cancer, according to the British Society of Gastroenterology 5
• The American Gastroenterological Association recommends that patients with a history of colorectal cancer that has been resected with curative intent should have a colonoscopy around the time of initial diagnosis to rule out synchronous neoplasms 6
• If the initial examination is normal, subsequent colonoscopy should be offered after 3 years, and then every 5 years if normal, as suggested by the American Gastroenterological Association 6
• Patients with long-standing, extensive inflammatory bowel disease (ulcerative colitis or Crohn's colitis) should undergo surveillance colonoscopy with systematic biopsies, according to the American Gastroenterological Association 6
• Surveillance typically begins after 8 years of disease in patients with pancolitis or after 15 years in those with left-sided colitis, as recommended by the American Gastroenterological Association 6

Contraindications for Colonoscopy

• The American Gastroenterological Association recommends that colonoscopy should not be performed in patients without alarm features (blood in stools, anemia, weight loss) unless age-appropriate colon cancer screening has not been performed 1, 2
• Patients with constipation without alarm symptoms do not require colonoscopy, according to the American Gastroenterological Association 1, 2
• Routine small bowel investigation (capsule endoscopy) is not advised in patients with sporadic duodenal adenomas, as suggested by the American Gastroenterological Association 7

Special Considerations

• Patients with obscure GI bleeding and associated anemia or overt bleeding with melena or maroon blood per rectum should undergo repeat endoscopic examinations, according to the American Gastroenterological Association 3, 4
• In patients with occult GI blood loss and no anemia, evaluation beyond colonoscopy is not warranted unless upper tract symptoms are present, as recommended by the American Gastroenterological Association 3, 4
• Patients meeting Rome II diagnostic criteria for irritable bowel syndrome without "red flags" (fever, weight loss, blood in stools, anemia, abnormal physical findings) do not routinely require colonoscopy, according to the American Gastroenterological Association 8
• However, a stool Hemoccult test and complete blood count are recommended for screening purposes in these patients, as suggested by the American Gastroenterological Association 8

Practical Approach

• For patients with acute lower GI bleeding, use the Oakland score to determine urgency (score >8 requires hospital admission and urgent colonoscopy), as recommended by the British Society of Gastroenterology 5
• For patients with constipation or IBS symptoms without alarm features, colonoscopy is not indicated, according to the American Gastroenterological Association 1, 2, 8
• For post-colorectal cancer surveillance, perform colonoscopy at time of diagnosis, then 3 years later, then every 5 years if normal, as suggested by the American Gastroenterological Association 6