Colonoscopy Content from the guide to life, the universe and everything


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A diagram of the lower gastrointestinal tract, with the stomach, small intestine and colon labelled.

A colonoscopy is an invasive investigative procedure undertaken to determine the reasons behind bowel problems. It involves a miniature camera being inserted into the anus, allowing the doctor to view the inside of the rectum and examine the large bowel. Someday they may have an equally effective but less invasive means of checking for a diseased colon, but not yet. With this test they will know exactly what they are dealing with and will be able to plan the follow-up measures accordingly.

The Symptoms

A colonoscopy is usually ordered by a GP if someone (hereafter called 'the patient') reports to him with any or all of the following symptoms:

The colonoscopy is also used to diagnose inflammatory bowel diseases like Crohn's disease and ulcerative colitis, and take a biopsy of any growths in the large intestine.

Advice for the over-50s

Age is a factor. If you are over the age of 50 your doctor will probably recommend a colonoscopy routinely. The American Cancer Society recommends that everyone has a colonoscopy to test for colon cancer at age 50. However, a quarter of people surveyed say their doctor had never discussed colon cancer screening with them, and another quarter said they didn't get screened because they had no symptoms of the disease. Considering colon cancer is the second largest cause of cancer-related death in the US, and bowel cancer is the third most common type of cancer in the UK, it would be prudent not to wait until you do have symptoms, but get yourself checked out anyway. Early detection equals a greater chance of fighting and beating the disease. Those with a family history of the disease shouldn't wait until they're 50.

Bobby Moore

Former England football captain Robert 'Bobby' Moore OBE (1941 - 93) died from bowel cancer and his family hold special fundraising events to raise awareness of this preventable disease.

Before the Procedure

The patient will receive a letter from the hospital clinic confirming their appointment, and a supply of laxative to ensure their bowels are emptied. The instructions to make up and take the laxative should be followed exactly: it's advisable not to plan for any meals after ingestion of the laxative. Certainly the patient shouldn't venture too far from the vicinity of a toilet. Plenty of water will need to be drunk because the laxative will cause dehydration. It will be requested that the patient abstain from eating some foods like red meat, which takes a long time to digest, several days beforehand, and may even be required to go on a liquid-only diet prior to the procedure.

If the patient is on any medication they should inform the clinic, as some types may have to be discontinued before the procedure, and the medicine in the original packaging should be shown to the staff at the clinic. The clinic appointment letter will have a telephone number if the patient wishes to phone and ask for advice.

Take an old towel with you (to sit on), sanitary towels and a change of underwear in case of accidents. You'll also need to keep sipping from a bottle of water to ensure your fluid levels are topped up.

You may get helpful feedback if you post a journal and tell your friends. Virtually everyone knows somebody who's had the procedure, and you will have moral support and lots of sympathy.

Having the Procedure

In the examining room the patient will be asked to lie on a bed or couch on their side with knees bent, in the foetal position. An anaesthetist will insert a cannula into a vein in the arm, wrist or hand, into which a sedative drug will be introduced to help the patient relax. Also given will be a pain-relieving drug (analgesia) to ensure minimal pain is felt; and a finger or thumb clip will be attached to monitor the oxygen level and check the patient's pulse rate during the procedure.

The procedure allows the doctor access to the large bowel via a colonoscope, which is a thin, flexible, fibre-optic tube, inserted into the anus. The colonoscope shows the lining of the colon (large bowel) to the doctor on a viewing screen. If the patient is awake, they are invited to watch the procedure onscreen, but this isn't compulsory. The patient will be sedated before the procedure, of course, but it depends on the patient's state of health and suitability for anaesthesia as to whether the dose administered is just to relax the patient or knock them out.

The doctor will examine the lining of the colon, which measures four to five feet in length. He may take a biopsy (a sample piece of suspicious tissue for microscopic examination), and will also be able to remove1 any polyps (small growths which may be causing the bleeding during bowel movement) that are detected. Polyps can be an early sign of colorectal cancer.

Singer and Oscar-winning actress Barbra Streisand had a routine colonoscopy in 2004 and a benign polyp was discovered. She later underwent an operation in Los Angeles' Cedars Sinai Hospital and the polyp was successfully removed.


The procedure will last as long as necessary depending on what is discovered, but the patient should normally be able to go home (with an escort) after an hour. The patient will not be fit to drive due to the anaesthetic administered. They should expect to be flatulent for some time, due to the air (used to inflate the colon during the procedure) needing an avenue of escape. The clearing of the bowels that is required before the procedure flushes out all of the good bacteria in your digestive system. After a colonoscopy, it's very important to eat pro-biotic yoghurts and such for a week or so afterwards to restore those bacteria. Those with cancer in remission, or who have had polyps removed, should return for rechecking at least every other year.

Personal Experiences from the UK

I don't know what's worse: the anticipation of the discomfort or the anguish at what might be found. The senna was disgusting. Having had explosive diarrhoea since 8pm, I daren't even go to bed. The worst part of the day has been the enforced no-feeding. I've been starving since breakfast, which wasn't even my 'normal' breakfast, because that wasn't on the 'permitted list' of allowed foods. I never want to end another day without my usual hot chocolate.
I went back for a proper colonoscopy. This involved fasting from the day before and, also the day before, taking a powerful laxative to completely empty and wash out the bowel. The fasting and emptying out felt really good. Then, with the patient under sedation, in they go with the fibre-optics, wiggling the camera around the various bends of the colon, and getting the full picture up on a large screen. It wasn't actually a particularly painful or uncomfortable experience, drugged up to the eyeballs as I was.

A Personal Experience from the USA

Day 1: The day before the procedure.

Liquid diet. Woke up at 6am, had coffee. Am taking the day off work. Did laundry: had a bottle of Ensure. Watched some TV. Made a large glass of lime gelatin for lunch, drank it while it was still liquid. 3pm: the hospital called to pre-register. Took insurance info over phone. 5pm: time for the laxatives. Instructions said take one bottle of saline laxative and divide into thirds, drinking a full glass of water or clear juice with each dose. 6pm drank final dose. Instructions further said if laxative action does not occur in two hours, drink Magnesium citrate. 6.30pm: first of many trips to toilet, (never used Magnesium citrate). Worried about dehydration - drank a lot of water which seemed to go right through me. When I stopped drinking, toilet action tapered off. Only had to get up three times during night to visit toilet.

Day 2: Procedure Day

Instructions said take second bottle of saline laxative in three parts then nothing by mouth until after procedure. Stool now has no solid faeces and is just cloudy liquid. After several more trips to toilet it becomes yellow liquid. 2pm: my wife drives me to hospital. Arriving at suite they have a small stack of paperwork to fill out. Then I say so long to my wife and go to a room where I remove my clothes and put on a hospital gown. The nurse attaches a wristband with my name and the name of my physician. The procedure room is now available: the person before me never showed up. The doctor complains that this is the third time she has cancelled. I talk to the doctor for a minute then am put to sleep. I wake up in recovery and am handed a couple of photos of my colon. The doctor says since they did not find anything we won't need to do this again for ten years. I am allowed to get dressed. I am unsteady on my feet having not eaten in over a day. I turn down the offer of a wheelchair. My wife and I make our way to the elevator and down to the cafeteria. With some food in me I feel stronger, but am under orders not to drive or use heavy machinery for the rest of the day. Home again I do a little Internet, watch some TV and turn in early. My wife comments that it is such a relief that all they found was a healthy colon. Next day I am back at work with no side effects. I shudder to think about the bill though. Medical procedures in the US are expensive and insurance doesn't always cover everything.

Colon Cancer Month

In Germany and the USA, the month of March has been declared Colon (Colorectal) Cancer Month. There's lots of information given in magazines, TV and on leaflets in Health Food shops, for instance, to raise awareness of the disease. In Germany, you have the right to have your stool checked (meaning the health insurance has to pay) once a year from the age of 50, and to have a colonoscopy every ten years from the age of 55. In case you have symptoms, they'll pay anyway. If a first grade relative (parent, sibling or child) has colon cancer, and let's say they got it at the age of 53, it is advised that you go for a test when you're 43, so ten years prior to the age your relative was diagnosed. First degree relatives of somebody with colon cancer have a two-to-three times higher risk of getting it too. If colon cancer occurred before the age of 60, the risk for the relatives rises to three-to-four times higher than 'normal' people.

Look After Yourself

This is an important diagnosis that you ought to consider having even if you have to pay for it yourself. In the US, approximately 30% do not have medical insurance. The cost (in 2007) would be somewhere around $1,300 US for a colonoscopy - a stool check would certainly be cheaper.

Thanks to early investigation and diagnosis, nine out of ten cases of colon cancer respond to treatment, enabling the patient to have a better prognosis and quality of life.

1Removal of polyps is called a polypectomy.

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