A colonoscopy, also known as a lower GI endoscopy, is a procedure that allows the physician to visually exam a patients large intestine. A colonoscope, a small diameter, flexible, lighted fiberoptic or video endoscope, is used for this procedure. This scope is inserted through the anus and is advanced through the large colon allowing the physician to visualize and capture pictures of any areas of concern. The colonoscope has open channels that allow the physician to advance other instruments that may be needed to remove lesions, polyps, etc. and take biopsies to aid in the diagnosis any suspicious looking areas. The "colonoscopy" procedure usually lasts from 15 to 30 minutes and requires sedation.
The flexible colonoscope is a remarkable piece of equipment that can be directed and moved around the many bends in the colon. Colonoscopes now come in two types. The original purely fiberoptic instrument has a flexible bundle of glass fibers that collects the lighted image at one end and transfers the image to the eye piece. The newer video endoscopes use a tiny, optically sensitive computer chip at the end. Electronic signals are then transmitted up the scope to a computer which displays the image on a large video screen. An open channel in these scopes allows other instruments to be passed through in order to perform biopsies, remove polyps, or inject solutions.
Reasons for the Exam
There are many types of problems that can occur in the colon. A patient's medical history, physical exam, laboratory tests and x-rays can provide information useful in making a diagnosis. However, directly viewing the inside of the colon by colonoscopy is usually the best exam. Colonoscopy is used for:
- Colon cancer
A serious but highly curable malignancy
Fleshy tumors which usually are the forerunners of colon cancer
- Colitis (Ulcerative or Crohn's)
Chronic, recurrent inflammation of the colon
- Diverticulosis and Diverticulitis
Pockets along the intestinal wall that develop over time and can become infected
- Bleeding lesions
Bleeding may occur from different points in the colon
- Abdominal symptoms
Such as pain or discomfort, particularly if associated with weight loss or anemia
- Abnormal barium x-ray exam
- Chronic diarrhea, constipation, or a change in bowel habits
A patient having a colonoscopy needs to be clean from stool which is achieved by the patient being on a CLEAR LIQUID DIET the day before the procedure beginning with breakfast. Your physician may prescribe additional preps to assist with the cleansing of the colon. Please see your physician for further instructions regarding the use of regular medications the day before and the day of your procedure. A patient having this exam is required to have someone that will be able to provide them with transportation to and from the center.
Colonoscopy is usually performed on an outpatient basis. The patient is mildly sedated, the endoscope is inserted through the anus and moved gently around the bends of the colon. If a polyp is encountered, a thin wire snare is used to lasso it. Electrocautery (electrical heat) is applied to painlessly remove the ployp. Other tests can be performed during colonoscopy, including biopsy to obtain a small tissue specimen for microscopic analysis.
The procedure takes 15 to 30 minutes and is seldom remembered by the sedated patient. A recovery area is available to monitor vital signs until the patient is fully awake. It is normal to experience mild cramping or abdominal pressure following the exam. This usually subsides in an hour or so.
When to Expect Results
The physician performing the procedure will speak with you and a family member or person(s) that has been given written permission for disclosure of your results. Following the exam in the recovery room, the physician will give you the results of the exam and advise you on further treatment or follow up should any be necessary. In the event that the physician removed a polyp or a biopsy(s) was taken, then you will be advised on when you can expect to receive these results. A pathologist will review the biopsy, and the results are usually available in ten days.
A colonoscopy is performed to identify and/or correct a problem in the colon. The test enables a diagnosis to be made and specific treatment can be given. If a polyp is found during the exam, it can be removed at that time, eliminating the need for a major operation later. If a bleeding site is identified, treatment can be administered directly and accurately to stop the bleeding. Other treatments can be given through the endoscope when necessary.
Alternative tests to colonoscopy include a barium enema or other types of x-ray exams that outline the colon and allow a diagnosis to be made. Study of the stools and blood can provide indirect information about a colon condition. These exams, however, do not allow direct viewing of the colon, removal of polyps, or the completion of biopsies.
Side Effects and Risks
Bloating and distension typically occur for about an hour after the exam until the air is expelled. Serious risks with colonoscopy, however, are very uncommon. One such risk is excessive bleeding, especially with the removal of a large polyp. In rare instances a tear in the lining of the colon can occur. These complications may require hospitalization and, rarely, surgery. Quite uncommonly a diagnostic error or oversight may occur.
Due to the mild sedation, the patient should not drive or operate machinery following the exam. For this reason, someone should be available to drive the patient home.
Colonoscopy is an outpatient exam that is performed with the patient lightly sedated. The procedure provides significant information used to diagnose a colon condition and determine which specific treatment should be given. In certain cases, therapy can be administered directly through the endoscope. Serious complications rarely occur from colonoscopy. The physician can answer any questions the patient may have.