Endoscopic examination of the upper and lower GI tract has been performed routinely since the late 1960's.
Over this time the equipment has become more sophisticated, with much better image quality and less difficulty for the patient. A great deal of effort has gone to increase the quality of the examination and to ensure absolute sterility of the equipment. Direct vision of areas of the GI tract which may be causing problems is greatly beneficial, as is the ability to take biopsy samples for analysis. Increasingly GI Endoscopy involves therapy and not just diagnosis.
Gastroscopy includes an examination of the oesophagus (gullet), stomach and the upper part of the duodenum (the very first part of the small bowel). It is extremely useful in the evaluation of dyspepsia, heartburn and vomiting. Actual ulcers and areas of inflammation can be visualised, and biopsied. If a cancer is present in the stomach or oesophagus, it will be seen and biopsied. Samples can be taken to test for Helicobacter infection. Rarer problems, such as the presence of dilated gullet veins in patients with Cirrhosis, can also be seen. The procedure rarely lasts for more than ten minutes and often less than five. Most patients find it acceptable to be wide awake, with a local anaesthetic spray on the throat, which makes the process quick and simple. If the patient does not feel they can cope with this, it can be done under a sedative injection which requires longer recovery and the rest of the day free (only rarely is full general anaesthetic needed). It is an extremely safe procedure, with an extremely low risk of complications.
At Colonoscopy, the aim is visualize the whole of the large bowel and in about half the examinations the lower small bowel (terminal ileum) can also be seen. It is necessary to take a powerful laxative beforehand so that the bowel is completely empty, and this is taken at home, usually on the day before the procedure. It is usual to perform the procedure under sedation and with some painkiller given immediately beforehand. Colonoscopy is extremely useful for evaluating symptoms of rectal bleeding and a change in bowel pattern. Problems such as Ulcerative Colitis, Crohn’s Disease and Colorectal cancers can also be visualized and biopsied. Any polyps that are seen can usually be removed immediately. All colonoscopies carry a very small risk of bowel damage (perforation) during the procedure. If a perforation does occur, an operation is often needed to repair it. However the overall risk is very small at about 1:1000. If a polyp is removed this risk may be doubled. The colon can also be imaged using a particular CT scan technique, but this does not include the ability to take biopsies or apply therapies.
At Flexible Sigmoidoscopy only the lower part of the large bowel is visualised. The advantage over and above Colonoscopy is that it can often be done without sedation, usually only needs preparation by enema immediately beforehand, rather than a full laxative the day beforehand, and a significant proportion of cancers and polyps are within the range of a Flexible Sigmoidoscopy. It is useful in the evaluation of rectal bleeding, and for the assessment of the severity of Colitis, but it is increasingly thought that most patients with new symptoms merit an examination of the whole of the colon.