HealthInfo Aoraki South Canterbury

Colonoscopy

Understanding colonoscopy

Your doctor has determined that colonoscopy is necessary for further evaluation or treatment of your condition. This information sheet has been prepared to help you understand the procedure. It includes answers to questions patients ask most frequently. Please read it carefully. If you have additional questions, please feel free to discuss them with the endoscopy nurse or your doctor before the examination begins.

What is a colonoscopy?

Colonoscopy is a procedure that enables your doctor to examine the lining of the colon (large bowel) for abnormalities. This is done by inserting an endoscope (a thin flexible tube that allows the doctor to see inside your bowel) through the rectum and advancing it slowly around the large bowel.

What preparation is required?

Your colon must be completely clean for the procedure to be accurate and complete. Your appointment letter includes instructions about the preparation you need to take beforehand, and a prescription to take to your chemist.

Please follow the instructions carefully. You may experience diarrhoea overnight before the examination but this is normal.

What about my current medications?

Most medications can be continued as usual, but some can interfere with preparation or the examination. Please bring any drugs or medications you are currently taking.

If you are taking other medications (including aspirin-based products) consult your doctor for additional instructions before your examination.

Please stop taking iron tablets four days before your examination.

If you have any of the following problems please contact the elective services coordinator on (03) 687-2127:

• Heart problems
• Epilepsy
• Pacemaker/defibrillator
• Diabetes
• Live alone
• Latex allergy (rubber)
• Currently taking warfarin, Pradaxa, or clopidogrel

What can I expect during colonoscopy?

It is our practice to give you sedation for pain relief and to relax you so that you may have little or no memory of the examination. Without this sedation you could experience abdominal discomfort. A few people request little or no medication. If that is your wish, please let us know at the time of the procedure.

There is often a feeling of pressure, bloating, or cramping at times during the procedure. The examination itself will usually be over within 30 minutes, although sometimes it takes longer.

Ninety percent of people are able to have the whole of the large bowel examined and the aim of the examination is achieved in the majority of patients.

What if the colonoscopy shows something abnormal?

If your doctor thinks an area of the bowel needs to be evaluated in greater detail, an instrument is passed through the colonoscope to obtain a biopsy (a sample of the colon lining). This is painless.

This specimen is sent to the Pathology Laboratory for analysis. Sometimes polyps or small mushroom-like growths are found which can be removed. This minor procedure, called a polypectomy, avoids an open abdominal examination. If polyps are found, they are removed because some can become cancerous over time.

What are the possible complications of colonoscopy?

Colonoscopy and polypectomy are generally safe when performed by physicians or surgeons who have been specially trained and are experienced in endoscopic procedures.

• One possible complication is a perforation or tear through the bowel wall that could require surgery. This is extremely rare, occurring about once per 1000 procedures.
• Bleeding may occur from the biopsy site or polypectomy. It is usually minor and stops on its own or can be controlled through the colonoscope. Rarely, blood transfusions or surgery may be required.
• Another uncommon potential risk is a reaction to the sedatives used.

What happens after colonoscopy?

• You will return to the ward for approximately 1.5 to two hours, until the sedation has worn off. You will be given something to eat and drink before you leave.
• You need to arrange for a friend or relative to be contacted when you are ready to go home to pick you up from the department approximately two hours after the examination. You should not be alone for the remainder of the day or overnight.
• Even if you feel alert after the procedure, your judgement and reflexes may be impaired by sedation. Do not drive a vehicle, operate any machinery, or drink alcohol for 24 hours, ride on public transport alone, sign any legal documents, or make any important decisions.
• You may have some abdominal cramping or bloating because of the air introduced into the colon during the examination. This should disappear quickly with the passage of flatus (gas). Generally you should be able to eat and drink after your colonoscopy.

Further information

You have been provided with this information to prepare you for this procedure because education is an important part of comprehensive medical care. If you have questions about your need for colonoscopy or alternative tests, do not hesitate to speak to your doctor. If you have questions that have not been answered, please discuss them with the endoscopy nurse or doctor before the examination begins.

Information provided by the Canterbury DHB. Page created March 2014.

Page reference: 89220

Review key: HICOL-20309