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DURING COLONOSCOPY, a flexible fiberoptic or video colonoscope is used to visualize, examine, and photograph the large intestine, including the anus, the rectum, and the sigmoid, transverse, and ascending colon. This procedure is most frequently used for cancer screening and for surveillance in patients with previous colon cancer or polyps. In addition, tissue biopsies can be obtained as needed and polyps can be removed and evaluated. Other uses of colonoscopy include the evaluation of patients with diarrhea of unknown cause, occult bleeding, or anemia; further study of abnormalities detected after a barium enema; and diagnosis, clarification, and determination of the extent of inflammatory or other bowel disease. Colonoscopy is contraindicated if the patient has a suspected or documented colon perforation, acute severe diverticulitis, or fulminant colitis.


Let's take a look at what you need to know about colonoscopy before, during, and after the procedure.


Prep with pep

The success of a colonoscopy depends on how well the colon is prepared. Here's what you need to do:


Tell your patient to maintain a clear liquid diet for 48 to 72 hours before the procedure, as ordered, and have him fast 8 hours before the procedure.


The health care provider will most likely prescribe a polyethylene glycol electrolyte lavage solution (Go-Lytely, CoLyte, Nu-Lytely) for your patient to cleanse the bowel. Instruct him to ingest the lavage solution at intervals over 3 to 4 hours. Adverse reactions to lavage solutions include nausea, bloating, cramps or abdominal fullness, fluid and electrolyte imbalance, and hypothermia. (Patients are often told to drink the preparation as cold as possible to make it more palatable.) The use of lavage solutions is contraindicated in patients with intestinal obstruction or inflammatory bowel disease.


Instruct your patient, especially if he's older, to maintain adequate fluid, electrolyte, and caloric intake while undergoing bowel cleansing.

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If your patient has diabetes, advise him to consult his health care provider about medication adjustment to prevent hyperglycemia or hypoglycemia resulting from the dietary modifications required in preparation for the test.

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If your patient has an implantable cardioverter defibrillator or pacemaker, advise him to consult his cardiologist before the test is performed.


If your patient has a prosthetic heart valve or a history of endocarditis, inform him that he'll require prophylactic antibiotics before the procedure.



Such a pretty view

Before colonoscopy is performed, the health care provider obtains informed consent and an opioid analgesic or sedative is administered to provide moderate sedation and relieve anxiety during the procedure. Glucagon may be administered, if needed, to relax the colonic musculature and to reduce spasm during the test.


Colonoscopy is performed while the patient is lying on the left side with his legs drawn up toward his chest. The patient's position may be changed during the test to facilitate advancement of the scope. Biopsy forceps or a cytology brush may be passed through the scope to obtain specimens for histology and cytology examinations. The procedure typically takes about 1 hour (see Picturing colonoscopy).


During the procedure, monitor for changes in your patient's oxygen saturation, vital signs, color and temperature of the skin, level of consciousness, abdominal distension, vagal response, and pain intensity. Monitor his cardiac and respiratory function continuously and give supplemental oxygen as ordered. Complications during and after the procedure can include cardiac dysrhythmias and respiratory depression resulting from the medications administered, vasovagal reactions, and circulatory overload or hypotension resulting from overhydration or underhydration during bowel preparation.


What a relief!!

After the procedure, your patient will be maintained on bed rest until he's fully alert. Here's what you need to do:


Observe your patient for signs and symptoms of bowel perforation, such as rectal bleeding, abdominal pain or distension, and fever.


Explain to him that he may experience abdominal cramps or discomfort caused by increased peristalsis stimulated by the air insufflated into the bowel and insertion and movement of the scope during the procedure.


Instruct him to report any bleeding to his health care provider.


Provide written instructions because he may be unable to recall verbal information if a sedative was used during the procedure.


Make sure your patient has someone to take him home if he underwent the procedure as an outpatient.



Not as bad as I thought

Colonoscopy is an important tool for the early detection of colon cancer. And with your help, your patient's anxiety about the procedure will be reduced and he'll get through the test with flying colors.


Learn more about it


Fishbach F. AManual of Laboratory and Diagnostic Tests, 7th edition. Philadelphia, Pa., Lippincott Williams & Wilkins, 2004:843-846.


Smeltzer SC, et al. Brunner and Suddarth's Textbook of Medical-Surgical Nursing, 11th edition. Philadelphia, Pa., Lippincott Williams & Wilkins, 2007:1135-1137.