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Introduction ⬇

Colonoscopy, also known as an optical colonoscopy, visualizes, examines, and photographs the large intestine with a flexible fiberoptic or video colonoscope inserted through the anus and advanced to the ileocecal valve. Air introduced through an accessory channel of the colonoscope distends the intestinal walls to enhance visualization. VC, also known as a screening CT colonography, uses CT images of the rectum and colon to screen for cancer. VC may be indicated in those patients who cannot undergo optical colonoscopy because of an occlusive mass or excessive spasm within the colon. An added benefit of VC is that it also allows for extracolonic findings, such as bronchogenic, ovarian, and kidney carcinomas.

Colonoscopy can differentiate inflammatory disease from neoplastic disease and can evaluate polypoid lesions that are beyond the reach of the sigmoidoscope. Polyps, foreign bodies, and biopsy specimens can be removed through the colonoscope. Photographs of the large intestine lumen can also be taken. Periodic colonoscopy is a valuable adjunct to the follow-up of persons with previous polyps, colon cancer, family history of colon cancer, or high risk factors. It is also helpful in locating the source of lower GI bleeding. It provides a safe way to perform presurgical screening and postsurgical surveillance of anastomotic suture lines. Colonoscopy is recommended as the primary screening tool for individuals of higher-than-average risk for colon cancer.

  1. Keep colon electrolyte lavage preparations refrigerated; however, the patient may drink the solution at room temperature. Use within 48 hours of preparation and discard unused portions.

  2. Before the procedure, complete blood count, prothrombin time, platelet count, and thromboplastin time results should be reviewed and charted.

  3. Persons with known heart disease may receive prophylactic antibiotics before testing.

  4. Patients should not mix or drink anything with the colonic washout preparation. Do not add ice or glucose to the solution.

  5. Patients with diabetes who take insulin are usually advised not to administer the insulin before the procedure but to bring it to the clinic.

Procedure ⬆ ⬇

  1. A clear liquid diet is usually ordered for 48–72 hours before examination. Have the patient fast for 8 hours before the procedure. Laxatives may be ordered to be taken for 1–3 days before the test; enemas may be ordered to be given the night before the test.

  2. Start an IV line and use for administration of sedatives and narcotic drugs. These medications are given to achieve a state of conscious sedation (see Chapter 1). Ensure that the patient is responsive enough to inform the practitioner of any subjective reactions during the examination. Ensure that resuscitation equipment is available.

  3. Perform continuous monitoring of the patient’s vital signs, cardiac rhythm, and oxygen saturation (pulse oximetry).

  4. On occasion, IV anticholinergic agents and glucagon may be used to relax bowel spasms.

  5. Have the patient assume the left-sided or Sims position and drape properly. Insert a well-lubricated colonoscope about 12 cm into the bowel. Ask the patient to take deep breaths through the mouth during this time. Introduce air into the bowel through a special port on the colonoscope to aid viewing. As the colonoscope advances, the patient may need to be repositioned several times to aid in proper visualization of the colon. Sensations of pressure, mild pain, or cramping are not unusual.

  6. Remember that the best views are obtained during withdrawal of the colonoscope. Therefore, a more detailed examination is usually performed during withdrawal than during advancement.

  7. If the patient is undergoing VC, the process takes about 15 minutes and, in most cases, does not require sedation.

  8. Follow guidelines in Chapter 1 for safe, effective, informed intratest care.

Clinical Implications ⬆ ⬇

Abnormal findings may reveal the following conditions:

  1. Polyps

  2. Tumors (benign or malignant)

  3. Areas of ulceration

  4. Inflammation

  5. Colitis, diverticula

  6. Bleeding sites

  7. Strictures

  8. Foreign bodies

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain the purpose, procedure, benefits, and risks of the test. Record preprocedure signs and symptoms (e.g., GI bleeding). If done as an outpatient procedure, the patient should arrange for a ride home and should leave valuables at home. Blood work, urinalysis, x-ray films, and scans should be reviewed and charted before the procedure. Record baseline vital signs.

  2. Confirm that the patient followed the bowel prep as ordered.

  3. Ensure that the patient followed any dietary restrictions ordered. Some patients will be on a clear liquid diet for 72 hours before the test, and then fasting, except for medications, after a clear liquid supper the evening before the test. No solid food, milk, or milk products are permitted. Strained fruit juices without pulp (e.g., apple, white grape), lemonade, Hi-C drink, water, clear liquid, Gatorade, Kool-Aid, Jell-O, popsicles, and hard candy are permitted, but no red or purple fluids are allowed.

  4. Administer an enema if oral bowel prep could not be completed or was ineffective. To be effective, a purgative must produce fluid diarrhea. This shows that unaltered small intestinal contents are emerging and colonic residue has been cleared. Enemas must be repeated until solid matter is no longer expelled (clear liquid returns). Do not administer a soapsuds enema as they are contraindicated because they cause increased mucus secretion as a result of irritant stimulation. Preparation is complete when fecal discharge is clear. If returns are not clear after 4 L of solution have been ingested, continue until returns are clear, up to 6 L total.

  5. Ensure that a legal consent form is signed and in the patient’s medical record.

  6. Confirm that the patient discontinued iron preparations 3 or 4 days before examination because iron residues produce an inky, black, sticky stool that interferes with visualization, and the stool can be viscous and difficult to clear. Confirm that aspirin and aspirin-containing products were discontinued 1 week before the examination because they may cause bleeding problems or localized hemorrhages.

  7. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

  8. Inform the patient to expect the following:

    1. Sleepiness during the test and inability to recall much of the procedure

    2. Abdominal pressure, mild pain, or cramping

    3. Passage of gas (expel flatus) or the urge to defecate, which is normal

    4. Need to assume various positions to aid with passing the colonoscope

Clinical Alert

  1. Solid food should never be taken within 2 hours before the oral cleansing regimen is begun.

  2. Orally administered colon lavage is contraindicated in the following conditions:

    1. Actual or suspected ulcers

    2. Gastric outlet obstruction

    3. Weight below 20 kg

    4. Toxic colitis

    5. Megacolon

  3. Relative contraindications for colonoscopy include the following conditions:

    1. Perforating disease of the colon

    2. Peritonitis

    3. Radiation enteritis

    4. Recent abdominal or bowel surgery

    5. Acute conditions of the anus and rectum

    6. Serious cardiac or respiratory problems (e.g., recent myocardial infarction)

    7. Situations in which the bowel cannot be adequately prepared for the procedure (i.e., fulminant granulomatous or irradiation colitis)

  4. No barium studies should be done during the preparation phase for colonoscopy.

  5. Bloating, nausea, and occasional vomiting after oral laxatives are common. Advise patient to adhere to instructions if at all possible.

Posttest Patient Care

  1. Explain that liquids or a light meal are permitted when fully awake.

  2. Observe stools for visible blood. Instruct the patient to report abdominal pain or other unusual symptoms because perforation and hemorrhage are possible complications.

  3. Monitor the blood pressure, pulse, respirations, and oxygen saturation, according to institutional policy, until the patient is fully awake.

  4. Warn the patient that they may expel large amounts of gas/flatus after the procedure.

  5. Review test results; report and record findings. Modify the nursing care plan as needed. Monitor for complications.

  6. Follow guidelines in Chapter 1 for safe, effective, informed posttest care. Provide written discharge instructions to outpatients. Outpatients should be discharged to the care of a responsible adult.

Clinical Alert

  1. Observe for the following possible complications:

    1. Perforations of the bowel

    2. Hypotensive episodes

    3. Cardiac or respiratory arrest, which can be provoked by the combination of oversedation and intense vagal stimulus from instrumentation

    4. Hemorrhage, especially if polypectomy has been performed

  2. If colon preparations are administered by lavage to an unconscious patient or to a patient with impaired gag reflexes, observe for aspiration or regurgitation, especially if a nasogastric tube is in place. Keep the head of the bed elevated. If this is not possible, position the patient on the side. Have continuous suction equipment and supplies readily available.

  3. Signs of bowel perforation include malaise, rectal bleeding, abdominal pain, distention, and fever.

Reference Values ⬆

Normal