II. Efficacy
- Identifies up 94-98% of Colon Cancer
- Identifies up to 98% of adenomatous polyps >1 cm (but only 74% <6mm)
- Efficacious and reduces mortality
- Preferred over other Colon Cancer screening modalities
- Reference
III. Interpretation: Criteria for a high quality Colonoscopy
- Minimal fecal residue following colon preparation
- Colonoscopy reaches the cecum
- Withdrawal time from cecum to Rectum is 6 minutes or more
- Complete removal of identified polyps (not piecemeal excision)
- Rex (2002) Am J Gastroenterol 97:1296-1308 [PubMed]
IV. Adverse Effects
- Minor common adverse effects
- Adverse effects of preparation medications
- Adverse effects of sedation
- Serious common adverse effects
- Perforations: 1 in 500-3000
- Rectosigmoid: 66%
- Cecal: 13%
- Ascending Colon: 7%
- Transverse Colon: 7%
- Descending Colon: 7%
- Major Bleeding: 1-2 in 1000 (0.1 to 0.6%)
- Most common with biopsy or lesion excision
- May occur up to 2 weeks after Colonoscopy
- Post-polypectomy Syndrome
- Abdominal Pain, Leukocytosis, peritoneal inflammation without perforation
- Onset within 2 weeks of polypectomy
- Perforations: 1 in 500-3000
- Uncommon
- Splenic Trauma
- Vasovagal reaction
- Endocarditis
- Rare
V. Findings: Polyps
- See Colonic Polyps
VI. Protocol: Home Medications Before Colonoscopy
- See Bowel Preparation
- No Antibiotic prophylaxis is needed in most cases
- Not indicated despite cardiac conditions, prosthetic joints, or vascular grafts
-
Anticoagulants
- Low dose Aspirin and NSAIDS
- Typically may be continued for all endoscopic procedures
- However, local protocols vary, and some may require Aspirin and NSAIDs be stopped first
- However, stable patients on Dual Antiplatelet Therapy will typically have Aspirin continued, and other agent held
- Antiplatelet Agents (Clopidogrel, Prasugrel, Ticagrelor)
- Low risk of bleeding (e.g. routine Colonoscopy)
- These agents are stopped in most cases, but may be continued if higher thrombosis risk
- Dual Antiplatelet Therapy patients who are stable
- Constinue low dose Aspirin and hold the other antiplatelet agent as below
- High risk of bleeding
- Low risk of thrombosis
- Stop Clopidogrel or Prasugrel for 5-7 days
- Stop Ticagrelor for 3-5 days
- High risk of thrombosis (e.g. drug eluting stent placed in the last year)
- Delay procedure
- Low risk of thrombosis
- Restarting after procedure
- No polyps removed: May restart immediately
- Polyps removed: Restart 24 hours after procedure
- Low risk of bleeding (e.g. routine Colonoscopy)
- Warfarin
- Low risk of bleeding (e.g. routine Colonoscopy): May continue Warfarin
- High risk of bleeding
- Low risk of thrombosis: Stop Warfarin for 5 days before procedure
- High risk of thrombosis (e.g. Mechanical Heart Valve, VTE within 3 months)
- Restarting after procedure
- No polyps removed: May restart immediately
- Polyps removed: Restart 12 hours after procedure
- Direct Oral Anticoagulants (DOACs, Apixaban, Rivaroxaban)
- Hold 1-2 before procedure (if normal Renal Function)
- Restarting after procedure
- No polyps removed: May restart immediately
- Polyps removed: Restart 48-72 hours after procedure
- Low dose Aspirin and NSAIDS
- Diabetes Medications
- Day prior to Colonoscopy
- Hold Sulfonylureas (e.g. Glipizide), Non-Sulfonylurea Insulin Secretagogues (e.g. Nateglinide)
- Consider decreasing evening premixed Insulin (e.g. 70/30) or Basal insulin by 50%
- Decrease Bolus Insulin by 50% (may use full Bolus Insulin dose if Carbohydrate Counting)
- May continue all other diabetes medications on day prior
- Day of Colonoscopy
- Consider giving partial Basal insulin dose on morning of procedure (esp. in Type I Diabetes Mellitus)
- Hold all other diabetes medications on the morning of procedure
- Day prior to Colonoscopy
- Other Medications
- Most other medications may be taken with a sip of water up to 3 hours before Colonoscopy
VII. Management: Suspected colonoscopic perforation
- Indications for immediate laparotomy
- Peritoneal signs
- Unreliable patient or comorbid conditions
- Large defect
- Poor Bowel Preparation
- Evaluation of stable, reliable patient
- Step 1: Obtain upright abdominal XRay
- Laparotomy for Free air
- Step 2: Obtain CT Abdomen
- Laparotomy for large perforation
- Step 3: Observe
- Indications
- Negative upright Abdomen
- Negative CT or contained perforation on CT
- Conservative protocol
- Patient kept NPO on Intravenous Fluids
- Prophylactic Antibiotics
- Serial exams, XRays, and White Blood Cell Count
- Laparotomy Indications
- Clinical deterioration
- Increased White Blood Cell Count
- Indications
- Step 1: Obtain upright abdominal XRay
VIII. References
- (2022) Presc Lett 29(5): 27
- Kavic (2001) Am J Surg 181:319-32 [PubMed]
- Wilkins (2018) Am Fam Physician 97(10): 658-65 [PubMed]