Experts in Bowel Care

Colonoscopy

Colonoscopy is a useful technique, which allows the surgeon to examine the inside of the large intestine (colon). It can be used to investigate rectal bleeding, anaemia or alteration in bowel habit; to examine parts of the bowel not clearly seen on a CT scan; to screen for polyps in patients with a family history of bowel cancer; or as part of follow-up where a polyp or cancer has been removed previously. Removing polyps has been proven to have a dramatic effect in reducing the risk of bowel cancer. The colonoscope is a flexible telescope, which is passed through the anus and rectum into the colon. In addition to direct visual inspection, small samples (biopsies) can be removed and sent for microscopic analysis.

Bowel preparation for a colonoscopy

In order to examine the colon it needs to be empty. This means that you have to take a powerful laxative prior to the examination. Instructions for taking the laxatives will be given to you. The timing depends on whether your examination is scheduled for the morning or afternoon. If you are diabetic or on any kind of anticoagulation then you will be given specific instructions about measures to take prior to the examination.

The day of the procedure

You will be admitted to the hospital and be asked to sign a consent form to the procedure if you have not already done so in clinic. You can drink right up to the procedure and take your normal tablets; though if you have a long drive you might wish to stop drinking in advance of that to avoid the need to stop on the way.

Sedation

Sedation helps to minimise discomfort and anxiety about colonoscopy but is not essential and the choice is yours. If you opt to have sedation, a small intravenous cannula is inserted to give you the two drugs used, midazolam and fentanyl, which induce drowsiness and provide pain relief. Midazolam also has an amnesic effect, so you may not have full recollection of the procedure. As you are sedated you will be given additional oxygen through the nose which is routine practice.

It may be possible to perform the procedure with Entonox (nitrous oxide gas, sometimes called laughing gas) which you can breathe in during the colonoscopy as you wish. This gives very good pain relief without sedation. Some patients prefer to have no sedation at all and then can drive etc immediately afterwards. 

You can discuss these options with your Consultant.  

The Procedure

The colonoscope is inserted and gently manipulated along the bowel. This can be aided by moving your position at times and occasionally some pressure can be applied to the tummy to help. It can take 10-45 minutes to perform but you will be away from the ward longer than this as after you will spend some time in the recovery area.

The images will appear on a screen, which you can watch if you like. Any abnormality can be photographed and some biopsy samples can be taken. If there are bowel polyps then these can usually be removed during the procedure.

Recovery

Following the procedure you will be returned to your room on the ward where the effects of the sedative will begin to wear off. Your surgeon will see you and explain the outcome of the examination. You may not recall all that is said because of the continuing effect of the sedative so it is useful to have a companion who can explain the findings later. The sedative however will affect your judgment so it is essential that your companion drive you home. You may get some abdominal colic as the gas used to inspect the bowel is passed but this will wear off quickly. You should not drive a car or operate machinery for 24 hours. The results of any biopsies sent for pathology analysis take a week or so to come through and these can be discussed when you are reviewed in clinic or will be sent to you in the post/via email.

Complications

Colonoscopy is a very safe procedure with few risks, but complications do occur rarely. The two main dangers are perforation and significant bleeding; the risk of these is highest after removal of a large polyp. Fortunately these are extremely rare – the risk of perforation is about 1 in a thousand and bleeding about 1 in two hundred; when they do occur, hospital admission is necessary and sometimes an operation is required to correct the abnormality. In our practice, no patients have required surgery despite performing many thousands of procedures.

Occasionally it is not possible to see all the way around the colon with the instrument because of the configuration of the bowel. Under these circumstances a CT scan may be required to look at the remaining colon.

CT Scan

What is a CT scan?

CT or Computerised Tomography scanning uses X-rays to provide images of anywhere in the body. CT scans can be performed for a number of reasons. Most commonly this is to diagnoses any underlying condition. Sometimes, CT scans can be performed to assess the response to treatment. The CT scanner can produce over 500 images of the internal structure of the body. This digital information can be viewed as 2D or 3D images of the internal organs on a computer. The images will be viewed and reported by an expert radiologist who specialises in the field.  The report is sent to your surgeon who will discuss the findings with you in the clinic. 

Do I need any preparation for a CT scan?

The radiology department that performs the scan will be in touch to make an appointment. They may ask various questions including:

• Do you have kidney disease?
• Are you diabetic?
• Are you allergic to iodine?
• Are you pregnant?
• Can you lie flat?
• Do you weigh more than 125kg?

Often, you will need to arrive half an hour before your appointment in case you need to drink liquid (oral contrast) that can outline the bowel for your scan. If you are having a specialized CT scan of your bowel the preparation is different (see CT Colonography). Usually, you will have had a small plastic tube, a cannula, inserted into a vein in your arm, to allow injection of a dye. This dye, usually based on iodine, helps to provide superior images of the blood vessels and internal organs. The injection may make you feel flushed and give you a metallic taste.

Once you are in the scanning room, you will be asked to lie on a couch, which then moves you through the circular scanner.  It does not take long and all you need to do is keep still. Most scans only take a few minutes, but you may be in the radiology department for an hour or so. Afterwards you can simply go home and should be safe to drive yourself.

CT Colonography

What is a CT colonography?

A CT colonography or virtual colonoscopy is a specialized CT scan of your colon. CT or Computerised Tomography scanning uses X-rays to provide images of anywhere in the body. The CT scanner can produce over 500 images of the internal structure of the body. This digital information can be viewed as 2D or 3D images of the internal organs on a computer. The CT colonography images can be analysed with specialized 3D software to give views as if you were travelling through the colon! The scan will be viewed and reported by an expert radiologist who specialises in the field.  The report is sent to your surgeon who will discuss the findings with you in the clinic.

Do I need any preparation for a CT colonography?

CT scanning can be used in a targeted fashion to look at the colon but it requires slightly different preparation to a standard CT scan.  This is designed to minimise the amount of stool in the bowel so the lining of the colon can be seen clearly.  The radiology department that performs the scan will be in touch to make an appointment.  They may ask various questions including:

• Do you have kidney disease?
• Are you diabetic? 
• Are you allergic to iodine?
• Are you pregnant?
• Can you lie flat?
• Do you weigh more than 125kg?

For 2 days prior to the scan you will need to be on a low residue diet and take an oral preparation called gastrograffin.  All the instructions will be sent to you from the radiology department and if you have any queries please call the department where the scan is being performed.  If you are diabetic there are specific extra instructions to follow so that your blood sugar level remains within reasonable limits.

Usually, you will have had a small plastic tube, a cannula, inserted into a vein in your arm, to allow injection of a dye. This dye, usually based on iodine, helps to provide superior images of the blood vessels and internal organs. The injection may make you feel flushed and give you a metallic taste.

Once you are in the scanning room, you will be asked to lie on a couch, which will move you through the circular scanner.  To obtain better images of the lining of your bowel, a small flexible tube will be inserted into your back passage, which is used to instil the colon with C0₂ gas.  This gas is absorbed quickly after the procedure but may make you feel a little bloated.  You may also have an injection of a medication, which relaxes the colon (Buscopan).  This might result in blurred vision for a short while, so you cannot drive until this effect has disappeared.  Following the examination you will be allowed home and can eat and drink as normal.

MRI Scan

What is an MRI scan?

MRI (Magnetic Resonance Imaging) works in a completely different way to CT scans. It does not involve X-rays so avoids the very small risk of radiation, but uses a strong magnetic field. This gains detailed information at an atomic level,  which is then reconstructed, using a computer, into images of the internal organs. In certain circumstances, MRI can produce superior information compared to CT such as imaging the small bowel, rectum and anal fistulae. It can also be used to clarify abnormalities seen on CT such as in the liver.

The images will be viewed and reported by an expert radiologist who specialises in the field.  The report is sent to your surgeon who will discuss the findings with you in the clinic.

Do I need any preparation for an MRI scan?

The radiology department that performs the scan will be in touch to make an appointment. As strong magnets are used for this scan, you will ask various questions including:

• Do you have metal implants such as joint replacements or vascular stents? 
• Do you have a pacemaker? 
• Are you pregnant?

The radiology department will send out information to you and do contact them if you have any questions.

Once you are in the scanning room, you will be asked to lie down in the tube of the scanner. Some patients may find this claustrophobic.  If you suffer from this in anyway do get in touch beforehand so we can minimise any fears or discomfort. All you need to do is lie still during the scan and as for a CT scan, you may require a cannula for contrast dye injection into a vein.  To ensure the best images the scans can take a while to perform, up to an hour.  Following your scan,  you can go home and should be safe to drive yourself.

Ultrasound Scan

What is an ultrasound scan?

Ultrasound scanning uses high frequency sound waves to images structures within the body. Ultrasound is very safe and does not involve X-rays so avoids the very small risk of radiation. Ultrasound gives excellent views of the solid organs such as the liver, spleen and kidneys. Ultrasound is also able to give dynamic “real-time” images and is very useful in guiding needles for targeted biopsy and small tubes to drain infections.

The scan will be performed and reported by an expert radiologist who specialises in the field. The report is sent to your surgeon who will discuss the findings with you in the clinic.

Do I need any preparation for an ultrasound scan?

The radiology department that performs the scan will be in touch to make an appointment. You may be asked to drink plenty of fluids so you have a full bladder at the time of your scan. The radiology department will send out information to you and do contact them if you have any questions.

Once you are in the scanning room, you may be asked to remove some clothing and wear a hospital gown. A small amount of clear jelly will be applied to the area to be scanned and an ultrasound probe used to perform the scan. The clear jelly will be removed at the end of the scan and you will be free to go home.