Norm of Colonoscopy
The intima of the large intestine is normally orange-pink in color, with folds and smooth indentations covered with mucus. Blood vessels may be visible below the epithelial surface.
Usage of Colonoscopy
Visualization of the mucosa of the entire colon and terminal ileum. Screening for intestinal abnormalities, including diverticula, polyps, tumors, ulcerative areas, infection, inflammation, irritation, bleeding sites, or strictures. Also used to study and biopsy or remove tumors, polyps, ulcerative colitis, parasitic disease, or other causes of diarrhea.
Description of Colonoscopy
A fiberoptic endoscopy study in which the lining of the large intestine is visually examined for inflammation or other changes of the mucosal surface and for bleeding sites or strictures. The test is indicated after a positive test for fecal occult blood or after a positive screening sigmoidoscopy or double-contrast barium enema, after bleeding of the lower GI tract, and when a client experiences changing patterns of bowel function. The American Cancer Society recommends a screening colonoscopy every 10 years in adults older than age 50. See also Sigmoidoscopy.
Professional Considerations of Colonoscopy
Consent form IS required.
Dysrhythmias, hemorrhage, myocardial infarction, perforation of colon, peritonitis, respiratory depression.
Recent myocardial infarction or pulmonary embolus; retained barium from an earlier study; second or third trimester pregnancy. Sedatives are contraindicated in clients with central nervous system depression.
- See Client and Family Teaching.
- A tap-water enema may be prescribed to be given just before the test and/or the client may ingest 28 tablets (42 g) of sodium phosphate or drink magnesium citrate the day before to cleanse the bowel.
- Sedation may be prescribed, such as 2–3 mg of midazolam and 80 mg of propofol IV just before procedure.
- Prepare suction equipment, emergency equipment, naloxone, lubricant, cytology brush, and containers of fixative for cytology specimens.
- Record baseline vital signs.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
- The client is positioned lying on the left side with knees flexed and draped for privacy and comfort.
- The flexible fiberoptic endoscope is inserted through the anus, and the rectum and colon are visualized. Insufflation occurs to aid in visualization. Insufflation of CO2 rather than air reduces abdominal pain and bowel distention after colonoscopy.
- Specimens may be obtained for cytologic testing.
- Photographs are taken of anomalies present.
- Polyps may be removed with colonoscopy biopsy forceps or an electrocautery snare.
- Place the tissue specimens in a fixative of 10% formalin. Place the cytology specimens in 95% ethyl alcohol (ethanol). Label the specimens and send them to the laboratory immediately.
- Observe the client and check vital signs every 15–30 minutes until fully recovered. If sedation was used, follow institutional protocol for post sedation monitoring. Typical monitoring includes continuous ECG monitoring and pulse oximetry, with continual assessments (every 5–15 minutes) of airway, vital signs, and neurologic status until the client is lying quietly awake, breathing independently, and responding appropriately to commands spoken in a normal tone.
- After the client has fully recovered, he or she may resume a normal diet.
- Observe for signs of colon perforation, which include abdominal pain or distention, malaise, fever, purulent rectal drainage, or lower gastrointestinal bleeding.
Client and Family Teaching
- Follow a clear liquid diet for 48 hours before the test and resume normal diet after the test.
- Bowel preparation is very important. A laxative is usually prescribed the evening before the test, unless contraindicated. Examples are 10 ounces of magnesium citrate or 3 tablespoons of castor oil.
- Make arrangements for transportation home after the procedure because driving is not permitted for 24 hours after receiving sedation.
- Take deep, slow breaths during the procedure. The urge to defecate is normal and can be relieved with this type of breathing.
- An increase in flatus is normal, and minor amounts of blood in the stool are expected after polyp removal.
Factors That Affect Results
- Soapsuds enemas irritate the mucosa, increase mucus production, and hinder visibility.
- Barium from any previous gastrointestinal work-up makes colon visualization impossible.
- Failure to clean the lower intestine makes colon visualization impossible.
- Strictures or other abnormalities from previous surgery, radiation, or severe, chronic inflammatory disease may interfere with passage of the colonoscope.
- The findings from this procedure may be useful to the surgeon during laparotomy to exclude other lesions.
- Virtual endoscopic magnetic resonance colonography that uses three-dimensional imaging does not identify polyps smaller than 5 mm.
- Music therapy has been shown to reduce anxiety and the need for sedation in persons undergoing colonoscopy.