An Introduction to Endoscopy
Endoscopy uses imaging modalities to allow visualiasation of internal structures not seen by other radiological modalities. Allowing for both diagnostic and therapeutic interventions.
Colonoscopy & Sigmoidoscopy
Colonoscopy is an examination to check the large bowel – colon and rectum, sometimes the last part of the small is also examined. This examination can be a simple diagnostic procedure – taking only a sample or it can be therapeutic – removing polyps and growths from the colon and rectum. Sigmoidoscopy is the examination of the left side of colon only.
Approximately one million colonoscopy procedures are performed in the UK each year.
A colonoscope is a long flexible tube with a light and camera inside. Doctors can see the inside of a patients’ bowel on a TV monitor. Colonoscopy examinations can last from 30 minutes to an hour. A bowel preparation is given 36 – 48 hours before the test to clear the bowel. This preparation is a type of strong laxative which patients the urge to visit the bathroom several times until the bowel is cleared of faeces. Patients are asked to be on low residue diets from 36 – 48 hours. A good preparation results in a satisfactory examination. Sigmoidoscopy does not involve any special preparation; patients are given an enema ½ an hour before the examination. This helps in a satisfactory examination.
CO2 gas is pushed inside the bowel to open the colon and rectum as these are normally collapsed. Patients can experience abdominal cramps and they have the freedom to ask for sedation and pain relief. A safe sedation is used, but patients are not supposed to work or drive for 24 hours and someone needs to accompany patients (who had sedation) at home for the first 24 hours. After the examination there is no special diet, patients can resume their normal diet. Patients can experience abdominal cramps for the first 24 hours, usually settled after passing flatus and opening the bowels.
Why people need a Colonoscopy / Sigmoidoscopy
- To find the cause of bowel symptoms
- To look for early cancer in patients deemed high risk – family history
- To follow up patients with previous cancers
- For polyp surveillance
- IBD (Ulcerative colitis / Crohn’s disease) diagnosis / surveillance
Complications and After care
- There is no special care after colonoscopy, patients can go back to their normal diet.
- If patients have been sedated for colonoscopy, patients are advised not to drive or use machinery, not to make any important decisions or sign a legal document for 24 hours. An escort is needed to take patients home and someone should stay with them for 24 hours.
- Colonoscopy is a safe examination but rarely bleeding or bowel perforation can occur. Risk of complications increases if a polyp is removed or any other therapeutic procedure is performed.
- Complications are suspected if a patient develops severe abdominal pain, temperature or bleeding from the back passage.
- In case of complications patients are advised to contact he endoscopist or attend a nearby A&E hospital.
Gastroscopy is an examination of the upper part of the gastrointestinal system. This examination involves looking in the oesophagus, stomach and duodenum which is first part of the small intestine. Gastroscopy is also called an Oesophago-gastro-duodenoscopy (OGD). Around a million gastroscopy procedures are performed in the UK each year.
A gastroscope is a thin flexible tube with a light and a camera. A gastroscope not only helps in diagnosis but is also used to take samples and perform some therapeutic procedures if needed.
Gastroscopy is mostly performed on an outpatient basis. Patients can have the test simply by numbing the throat with a local anaesthetic spray or combing numbing of throat with sedation. Safe sedation is used.
A gastroscope is passed through the mouth and it glides down the throat into the oesophagus, then goes through stomach and finally in to the duodenum. A simple diagnostic examination takes about 10 – 15 minutes and longer when a procedure is performed.
Complications and after care
- Gastroscopy is a very safe procedure rarely causing oesophageal or gastric perforation or bleeding can happen.
- Patients might experience a sore throat after the procedure, this is self-limiting, patients get better within a couple of days. Gargling with warm water can help.
- Patients who were sedated are advised not to drive or use machinery, not to make any important decisions or sign a legal document for 24 hours. An escort is needed to take patients home and someone should stay with them for 24 hours.
- If the patient develops severe chest or abdominal pain, they should contact the endoscopist or nearby A&E hospital.