Colonoscopy Screening in Pennsylvania
Colonoscopy is a direct visual examination of the inside lining of the colon (large intestine) with a lighted flexible tube. These instruments transmit light with a flexible bundle of glass fibers. Most of the newer instruments now utilize a tiny TV camera at the end of the instrument to transmit a visual image to a video monitor. An open channel in the endoscope allows other instruments, such as biopsy forceps, to pass through the endoscope. The colon is about five feet long and has a number of functions, including removal of water from liquid stool.
Reasons to have a colonoscopy:
- Colon cancer prevention: Most colon cancers arise from within non-cancerous tumors (polyps) that have been growing for more than five to ten years. Polyps cause no symptoms. Looking for polyps periodically, and removing polyps found, has been shown to be an effective way to reduce the risk of colon cancer. Please refer to Prevention of colorectal cancer
- Bleeding and anemia: The underlying cause of rectal bleeding or iron deficiency anemia can often be detected by colonoscopy.
- Cancer: In addition to preventing colon cancer, early diagnosis of cancer dramatically increases the rate of cure. Laser therapy can be applied through a colonoscope for palliation of advanced cancers.
- Diarrhea: When diarrhea has been continuing and a cause has not been found, colonoscopy can be useful in finding the reason for the diarrhea. A variety of types of colitis can be identified by visual inspection and by biopsy of the lining of the colon.
- Pain: Hemorrhoids and fissures may cause pain around the anus and can be diagnosed with sigmoidoscopy. Tumors and diverticulosis can also cause pain in the lower abdomen and rectal area.
- Preoperative evaluations: The extent of diverticulosis or colitis can be determined with colonoscopy so that surgery, when needed, can be appropriately applied. In addition, when surgery is contemplated for one section of the colon, the remainder of the colon can be inspected with colonoscopy so as to reduce the likelihood of unexpected findings.
- Abnormal barium enema x-ray: Abnormalities identified on barium enema often need to be confirmed with direct look and/or biopsy.
Risks of the examination
Because air is used to inflate the colon during the examination, bloating and abdominal distension are the most common side effects of the examination. Within one hour, these symptoms are usually gone. If tissue is removed from the colon (biopsy or polypectomy), there may be a small amount of blood observed after the examination. A physician should be notified if the bleeding continues or if there is more than a small amount of blood seen. A tear in the colon is a rare complication and may require surgery for repair.
Description of the procedure
Colonoscopy is usually done in an outpatient setting with the patient sedated. Generally, the patient is lying on the left side. A rectal examination is done by using a lubricated, gloved finger. The instrument, which is approximately the same diameter as the human finger, is then gently inserted into the rectum and advanced into the colon. If a polyp is found, a thin wire snare is used to lasso it. Electrocautery is applied painlessly to remove it. Biopsies can be taken to further examine areas that look abnormal. During the examination, occasional momentary cramping may be experienced in the lower abdomen. However, because of the sedatives used, discomfort is generally minimal. The examination is usually completed within 10 to 30 minutes. The patient is then generally observed in a recovery area for about an hour or until fully awake.
Preparation for the examination
In order for the doctor to see the inside lining of the colon, it must be cleaned out before the examination. This is usually accomplished by limiting the diet to clear liquids and taking laxatives or drinking a bowel cleansing solution the day before the examination. Your doctor or a member of our staff will provide you with specific instructions.
Check with your doctor if you take blood thinners (Coumadin) or diabetes medicines.
You must have someone drive you home. You will not be allowed to drive for 12 hours after receiving sedation.
Sigmoidoscopy allows for examination of only the lower third of the colon and is therefore less thorough than colonoscopy. However, the preparation the night before is less extensive, sedation is generally not needed, and therefore, it is much less inconvenient for a patient to schedule. Barium enema X-ray provides an indirect look at the lining of the lower intestine, is less accurate than colonoscopy, and does not allow for biopsy, removal of polyps, or direct visual assessment. Abnormalities detected on a barium enema usually need to be confirmed with colonoscopy or CT scan. Virtual colonoscopy produces images of the colon by computer manipulation. It is more accurate than barium enema but not as good as colonoscopy at finding small polyps or identifying flat abnormalities of the lining of the colon. Like the barium enema, it does not allow for biopsy or removal of polyps. Perhaps the greatest problem with virtual colonoscopy is that 30% of people have colon polyps. If they are found by virtual colonoscopy, then standard colonoscopy must be done to remove the polyps, and, therefore, the individual must undergo two procedures.