A colonoscopy helps detect changes or abnormalities in the large intestine (colon) and rectum. This HealthHearty article describes the colonoscopy procedure, and also provides information on how to prepare for it.
A colonoscopy is performed to examine the entire colon and the rectum visually for any abnormalities. As it allows to examine the large bowel (large intestine or colon) from inside, it is the first procedure to be performed, if your physician suspects colon cancer or colorectal cancer. During the procedure, a colonoscope, which is a long (about 3 feet), flexible, thin (less than 1 inch) tube with a camera at its tip, is inserted into the colon via rectum. The images sent by the camera are received on a monitor, and are analyzed by the doctor.
In the United States alone, over a million colonoscopies are performed every year. Most of the people who undergo colonoscopy are over the age of 50 years. The procedure helps rule out the possibility of colon cancer. It has been observed that the results are normal 80% of the time. An abnormal result does not necessarily mean cancer. The lifetime risk of developing colorectal cancer is about 1 in 20 (5%). This risk is slightly lower in women than in men. As the polyps can be found and removed before they can develop into cancerous tumors, the death rate for colorectal cancer has been dropping in both men and women for more than 20 years. Colonoscopy helps evaluate symptoms like blood in stools, chronic abdominal pain, diarrhea, and changes in bowel habits.
Getting Ready for Colonoscopy
If you are pregnant, diabetic, suffering from lung/heart diseases, or if you are on blood thinning medication, ensure that your doctor is well aware of this fact. Also discuss, if you have an artificial heart valve, or if you were asked to take antibiotics before a surgery or dental procedure. Do not stop your medicines without discussing with the doctor. And do not forget to inform your doctor about the medicines that you are allergic to.
For the results to be accurate, your doctor will give you a few instructions, that will ensure that your colon is clear of fluids and stools, which otherwise can obstruct the view of the colon and the rectal lining. The doctor may ask you to limit or eliminate solid foods for a few days before the test. 24 hours prior to your procedure, the doctor will advise you to:
- Discontinue any medication containing iron, as it changes the color of the colon lining.
- Take the prescribed laxative.
- Avoid solid and opaque foods.
- Consume only nonalcoholic drinks like juices and soups.
- Avoid food that is red in color, as it can be confused with blood.
- Stop the intake of food and liquids 8-10 hours prior to the procedure.
- Bring someone with you. Somebody should accompany you home, as you will be drowsy with the sedative.
Procedure for Colonoscopy
- For a colonoscopy to be successful, complete cleansing of the bowel is essential. To empty the intestines before the procedure, you might be given two enemas. They can be given 1-2 days prior to the procedure. You should not consume any solid food or liquids on the night before the test is to be performed. You are expected to fast until the test is finished. You can resume your normal diet half an hour after the test.
- When performed by an experienced physician, colonoscopy can be relatively painless. But, due to the nature of the procedure, it can cause anxiety, and in some cases pain. Hence, to help people tolerate the procedure better, and to minimize the discomfort, the physician may administer anesthesia or a mild sedative along with a pain medication.
- Before the procedure begins, you will be asked to lie on your left side. The doctor will insert the colonoscope into the rectum. The colonoscope will be long enough to reach the other end of the colon. It comes with a fiber optic light and a channel through which air can be inserted to inflate the colon. The arrangement helps the doctor to get a better view of the colon. Mild cramping, an urge to pass gas, or to go to the toilet may be felt. This is normal, and there is no need to panic. Talk to the doctor, if there is too much of discomfort.
- The doctor will examine the video images sent by the tiny camera attached to the colonoscope gliding through the colon. The other end of the instrument will be connected to a monitor. You may be occasionally asked to change your position, so that the doctor can get a better view of your colon.
- If the doctor comes across any abnormalities like polyps, he will remove them using tiny tools that can be passed through the colonoscope. He can also take tissue samples (for biopsy), inject solutions, and cauterize tissues. When the examination is completed, the doctor will slowly withdraw the colonoscope ensuring that all the extra air is released. The entire procedure takes less than an hour.
After the Colonoscopy Procedure
- It takes about an hour after the procedure to recover partially from the effects of the sedative or the anesthesia. You will need someone to take you home, as you will be very groggy. And it can take an entire day for you to recover completely.
- Further, you may also feel bloated, and may pass gas for a few hours after the procedure. This too is completely normal, and walking about a bit will help lessen the discomfort. However, if the pain and discomfort continues to persist, contact your doctor.
- Small amount of blood can be seen in the bowel movements after the procedure. This is not a cause for any alarm. But, you need to contact your doctor if you continue to pass blood or blood clots, or if you develop a persistent fever of 100 degrees F. or higher.
If the colon is not completely cleansed, the doctor could miss a few abnormalities. Based on his experience, the doctor can either suggest to repeat the procedure immediately, or in a years time, depending on the outcome of the examination, and how satisfied he was with the entire procedure. Colonoscopy helps confirm certain conditions such as diverticula, Crohn’s disease, ulcerative colitis, colon polyps, and colon cancer.
Although the exact instructions given before a colonoscopy may vary from clinic to clinic, we hope that this article has helped clear some doubts that you had regarding a colonoscopy.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.