Colorectal
Diagnostics and Tests
It may be necessary for you to have one or more of the following investigations.
- Blood Tests
- Sigmoidoscopy
- Colonoscopy
- Barium Enema
- Computerised Tomography (CT scan)
- CT Colonography (Virtual Colonoscopy)
- MRI – Magnetic Resonance Imaging Scan
- Ultrasound
Blood Tests
Blood tests are taken to check your general health.
Sigmoidoscopy
A small tube with a bright light at the end is inserted into the back passage so that the lower bowel can be seen. The examination takes no more that two to three minutes to complete during which time some air is pumped into the bowel.
You may feel the need to pass wind but try not to worry, the doctor is aware that this may happen. Biopsies (sample of tissue) may be taken if anything abnormal is seen.
Colonoscopy
For this investigation a laxative is given to help clear out the bowel. It is also normal to give patients a sedative to help relieve any fears and anxieties.
The examination involves a flexible telescope being inserted into the back passage so that the colon can be looked at. If anything abnormal is found biopsies will be taken.
Barium Enema
This is an X-ray procedure during which a dye is introduced into the back passage via a tube. Some air will also be put into the bowel. The air and barium liquid will be drained out.
Computerised Tomography (CT scan)
A CT scan is a special type of X-ray examination in which an X-ray machine is connected to a computer which produces cross-sectional images of the body.
For the scan you will need to lie on a table and be passed through the scanner which is a ring like structure.
Some patients need to have a special drink before their scan which contains some X-ray dye to improve the quality of the scan pictures
CT Colonography (Virtual Colonoscopy)
During virtual colonoscopy a small tube is placed just inside the back passage.
Some harmless carbon dioxide gas is introduced through this in order to inflate the bowel. No sedative is given.
Two X-ray CT scans are then taken, one with you lying on your tummy and one with you lying on your back.
Each CT scan takes about 20 seconds and you will be asked to hold your breath during this. The whole examination takes about 20 minutes.
MRI – Magnetic Resonance Imaging Scan
MRI uses a strong magnetic field to produce detailed images of the rectum and sometimes the liver.
The scanner uses a large cylindrical magnet which surrounds the patient in the form of a large tunnel. This is painless and takes 30-40 minutes.
Ultrasound
An ultrasound scan uses beams of sound directed via a small device like a microphone placed onto the abdomen, which is covered with a gel to improve conduction.
The sound is reflected back onto a computer showing internal organs on a monitor for the doctor to view.
An ultrasound will take approximately 15-20 minutes and is completely painless.