Gastrointestinal Diagnosis

There are numerous investigative methods now available to diagnose gastro-intestinal conditions. They fall into one of two categories: Upper Gastro-Intestinal and Lower Gastro-Intestinal.

Upper Gastro-Intestinal Investigations

Diagnostic Endoscopy

There are many upper gastrointestinal investigations. The commonest of these is diagnostic endoscopy.  Modern endoscopes are only a little larger than a drinking straw and allow inspection of the whole of the oesophagus stomach and duodenum. The investigation is very accurate and is the main method of diagnosing stomach ulcers, duodenal ulcers, Helicobacter pylori infection, gastric polyps, cancers of the stomach, and oesophagus and Coeliac Disease. Complications are extremely rare for simple diagnostic endoscopy. For full details of endoscopy go to.

Many therapeutic and diagnostic procedures can be performed at the same time as endoscopy. Barrett’s oesophagus can be diagnosed and examined in more detail under magnification or following the application of dyes to target specific areas for biopsy. Bleeding sources (e.g. bleeding arteries in the base of ulcers, vascular malformations and bleeding polyps) can all be treated by the application of metal clips. Oesophageal strictures can be dilated by solid dilators passed over stainless steel guide wires or by balloons.  Metal stents can be placed through malignant strictures. Varicose veins of the oesophagus due to liver disease can be injected or banded.


X-rays taken while swallowing Barium have largely been superseded by endoscopy. This investigation still remains valuable in the diagnosis of swallowing disorders.  Muscular disorders can also be examined with motility probes which allow an accurate record of muscle contraction. This can be associated with PH measurement to determine acid reflux into the oesophagus.

Endoscopic Retrograde Cholangio Pancreatography

A special form of endoscopy called endoscopic retrograde cholangio pancreatography can be used to examine the pancreas and biliary tree. In this test a side viewing endoscope is inserted into the duodenum and access can be gained to the pancreatic and bile duct to diagnose stones, tumours and other abnormalities. A variety of therapeutic procedures including removal of stones and the insertion of stents can be performed. For further details on ERCP go to.

Endoscopic Ultrasound

Endoscopic ultrasound allows for much for accurate assessment of structures in or close to the oesophagus, stomach, duodenum and pancreas because the probe situated on the end of the endoscope can be closely approximated to the area being examined. It is particularly useful in the assessment of tumours in the wall of the gut, a detection of bile duct stones and the assessment of pancreatic abscesses and tumours.

Lower Gastro-Intestinal Investigations

Rigid Sigmoidoscopy

A rigid sigmoidoscope is a steel tube with an illuminating device which can be used to examine the rectum and rectosigmoid junction. The procedure is usually undertaken without sedation and can be uncomfortable.

Flexible Sigmoidoscopy

Flexible sigmoidoscopy uses a flexible video endoscope and can be undertaken after only limited bowel preparation. It allows the distal 60 to 90cm of the bowel to be examined. However full visualisation of the bowel requires colonoscopy.


Colonoscopy involves examination of the whole of the large bowel with a flexible video instrument and can be used to examine the last part of the small bowel. A vigorous bowel preparation is required because it is absolutely essential that the bowel has been fully cleared of faecal material if an accurate examination is to be undertaken. Colonoscopy is usually undertaken with intravenous sedation. A variety of therapeutic procedures can be undertaken during colonoscopy.  This will include the removal of polyps. In the application of heat or metal clipping devices to bleeding lesions, the dilatation of strictures and the insertion of metal stents. Colonoscopy is the most accurately investigation for diagnosing colonic cancer and polyps.