Chapter 64. Colonoscopy

• • Chronic diarrhea.

  • Lower gastrointestinal bleeding.

  • Abdominal pain.

  • Evaluation of radiographic abnormalities.

  • • Ulcerations.

    • Filling defects.

    • Strictures.

  • Initial diagnosis and follow-up evaluation of inflammatory bowel disease.

  • Removal of foreign bodies.

  • Dilatation of colonic strictures.

  • Diagnosis and removal of polyps.

  • Histopathologic evaluation of pinhead-sized biopsy specimens.

Absolute

• • Cardiorespiratory collapse.

  • Hemodynamically unstable patient.

  • Unstable airway.

  • Intestinal perforation.

  • Peritonitis.

  • Cervical spine trauma.

  • Toxic, fulminant colitis.

Relative

• • Coagulopathy (prothrombin time > 18 sec).

  • Thrombocytopenia (platelet count < 100,000/μL).

  • Intestinal tract surgery within previous month.

  • Food intake within previous 6 hours.

  • Bowel obstruction.

• • Fiberoptic or video endoscopes.

  • Biopsy forceps.

  • Snares.

  • Nets and baskets.

  • Heater probes.

  • Electrocautery probes and snares.

  • Balloon-dilation devices.

• • Anesthesia complications.

  • Bleeding.

  • Perforation.

• • Biopsies are required because characteristics of many disorders may only be detectable under the microscope.

• • Obtain medical history and physical examination for clearance from pulmonary, cardiovascular, and hematologic standpoints.

  • Obtain laboratory tests, if needed.

  • • Hemoglobin levels.

    • Platelet count.

    • Prothrombin time.

    • Partial thromboplastin time.

  • Primary care providers can prepare patients and families by explaining that the colonoscopy provides detailed diagnostic information and rarely causes complications (1/2000 chance of significant bleeding or perforation).

  • Have parents sign a consent form.

  • Bowel preparation.

  • • Clear liquids for 24 hours prior to procedure (infants: 12 hours); avoid red-colored fluids.

    • Sodium phosphate, magnesium citrate, MiraLax (for 4 days), polyethylene glycol (PEG) lavage solution, enemas (saline or phosphate) if needed.

    • No oral intake after midnight before procedure.

  • Antibiotics for endocarditis prophylaxis in at-risk patients.

  • Antibiotics for immunosuppressed patients or those with central lines (controversial).

• • Left lateral decubitus.

  • Supine.

• • The colon is divided into 5 sections:

  • • Sigmoid.

    • Descending.

    • Transverse.

    • Ascending.

    • Cecum.

  • The rectum as well as the sigmoid and descending colon are the areas where juvenile polyps and ulcerative colitis are commonly seen.

  • The junction between the descending and transverse colons is usually marked by the bluish blush of the spleen.

  • The transverse colon can be recognized by the triangular-shaped folds.

  • The junction between the transverse and ascending (or right colon) is usually marked by the bluish blush of the liver.

  • The cecum can be verified by finding the small appendiceal opening, the ileocecal valve, or seeing light transilluminate the right lower quadrant.

  • The cecum and terminal ileum are often involved in Crohn disease.

• • Administer oxygen by nasal cannula.

  • Start intravenous sedation or gas anesthesia via an endotracheal catheter.

  • • Heavier sedation is required for colonoscopy than for upper endoscopy.

    • Sedation options include midazolam plus fentanyl for conscious sedation, but it is rarely sufficient for full ...