Colonoscopy
What is a colonoscopy?
A colonoscopy enables your doctor to examine the lining of your colon (large intestine) for abnormalities by inserting a flexible tube as thick as your finger into your anus and slowly advancing it into the rectum and colon.
How do I prepare for the colonoscopy?
Your doctor will prescribe you a bowel prep, which works similar to a laxative, that will enable the doctor to view the colon wall during the colonoscopy exam. The bowel prep, which is usually in a liquid form, will be taken the day prior to the exam. You will also need to follow a clear liquid diet the full day prior.
Should I continue my current medications?
Most medications can be continued as usual, but some medications can interfere with the preparation or the examination. Inform your doctor about medications you're taking, particularly aspirin products, arthritis medications, anticoagulants (blood thinners), insulin or iron products. Also, be sure to mention allergies you have to medications.
Alert your doctor if you require antibiotics prior to dental procedures, because you might need antibiotics before a colonoscopy as well.
What happens during a colonoscopy?
Colonoscopy is well-tolerated and rarely causes much pain. You might feel pressure, bloating or cramping during the procedure. Your doctor gives you a sedative to help you relax and better tolerate any discomfort.
In some cases, the doctor cannot pass the colonoscopy through the entire colon to where it meets the small intestine. Although another examination might be needed, your doctor might decide that the limited examination is sufficient.
What if the colonoscopy shows something abnormal?
If your doctor thinks an area needs further evaluation, he or she might pass an instrument through the colonoscopy to obtain a biopsy (a sample of the colon lining) to be analyzed. Biopsies are used to identify many conditions, and your doctor might order one even if he or she doesn't suspect cancer. If colonoscopy is being performed to identify sites of bleeding, your doctor might control the bleeding through the colonoscopy by injecting medications or by coagulation (sealing off bleeding vessels with heat treatment). Your doctor might also find polyps during colonoscopy, and he or she will most likely remove them during the examination. These procedures don't usually cause any pain.
What are polyps and why are they removed?
Polyps are abnormal growths in the colon lining that are usually benign (non cancerous). They vary in size from a tiny dot to several inches. Your doctor can't always tell a benign polyp from a malignant (cancerous) polyp by its outer appearance, so he or she might send removed polyps for analysis. Because cancer begins in polyps, removing them is an important means of preventing colorectal cancer.
How are polyps removed?
Your doctor might destroy tiny polyps by fulguration (burning) or by removing them with wire loops called snares or with biopsy instruments. Your doctor might use a technique called "snare polypectomy" to remove larger polyps. That technique involves passing a wire loop through the colonoscopy and removing the polyp from the intestinal wall using an electrical current. You should feel no pain during the polypectomy.
What happens after a colonoscopy?
Your physician will explain the results of the examination to you, although you'll probably have to wait for the results of any biopsies performed.
You should be able to eat after the examination, but your doctor might restrict your diet and activities, especially after polypectomy.
What are the possible complications of colonoscopy?
Colonoscopy and polypectomy are generally safe when performed by doctors who have been specially trained and are experienced in these procedures.
One possible complication is a perforation, or tear, through the bowel wall that could require surgery. Bleeding might occur at the site of biopsy or polypectomy, but it's usually minor. Bleeding can stop on its own or be controlled through the colonoscopy; it rarely requires follow-up treatment. Some patients might have a reaction to the sedatives or complications from heart or lung disease.
Although complications after colonoscopy are uncommon, it's important to recognize early signs of possible complications. Contact your doctor if you notice severe abdominal pain, fever and chills, or rectal bleeding of more than one-half cup. Note that bleeding can occur several days after.