Colonoscopy is considered the gold standard for the diagnosis of colon and rectal polyps and malignancies. It is a day procedure examination of the large intestine (colon). It can be performed after the bowel has been cleansed with special drinks which empty the colon. After you are given sedation, a slim flexible tube with a camera on the end is introduced into the back passage (anus) and gently advanced within the colon, so the inside of the colon can be viewed on a screen. It is possible to identify abnormalities including inflammation, detect growths, and remove any polyps during the procedure. After the age of 50 polyps are common. The removed polyps are collected to be reviewed under a microscopic. Most are benign but polyps can change with time into cancers so it is important to remove them. Removing polyps reduces the risk of developing bowel (colorectal) cancer.

Colonoscopy assessment is advised if you have any of the following symptoms:

• rectal bleeding (bright, altered blood or blood mixed with stool)
  
• persistent altered bowel habit (new constipation or loose stools, or a change in stool frequency)
  
• a sense of incomplete emptying
  
• recurrent or persistent abdominal discomfort/pain
  
• unexplained tiredness or anemia (iron deficiency)

If you notice any of these symptoms it does not mean you have colorectal /bowel cancer, but you are advised to have your bowel checked to exclude it

In Australia, colorectal cancer is the second commonest cause of cancer related deaths. A significant family history of bowel cancer includes a close relative (eg. parent, brother, sister, child) who has had bowel cancer under the age of 55, or if more than one relative on the same side of your family has had bowel cancer. In these cases colonoscopic surveillance is advised.

However more then 75% of people who develop colorectal cancer do not have a history of any relatives with colorectal cancer.

The complication risks of colonoscopy are less than 1% with the most serious being perforation (hole in the bowel); or bleeding (rarely associated with polyp removal). There is no other test which is as sensitive to detect colorectal cancers, or polyps (and allows removal of polyps). Approximately 95% of the colon can be viewed at colonoscopy. The number of colon cancers and death from colon cancer have been reduced due to colonoscopy.

To evaluate and view the oesophagus, stomach and duodenum a gastroscopy (also known as upper endoscopy) can be undertaken. Gastroscopy can be used to evaluate indigestion, heartburn, stomach pain, trouble swallowing and anaemia. Problems like stomach and duodenal ulcers; inflammation caused by reflux at the end of the oesophagus; and bleeding sources can be identified. This is a procedure where after a time of fasting, sedation is given and a thin flexible tube with a camera at the tip is placed through the mouth and gently moved into the oesophagus (food tube or gullet), stomach and duodenum. Tissue samples can be taken for analysis if needed. Assessing duodenal /small bowel tissue samples is essential to diagnose coeliac disease for instance.

As well, therapies can be facilitated during a gastroscopy. If needed during a gastroscopy swallowing difficulties can be helped by stretching the food tube; polyps can be removed; bleeding can be stopped; or even foreign bodies accidentally swallowed, can be removed.

Fortunately gastroscopy is usually well tolerated with complications being rare. Major complications, for example, perforation (a tear in the wall of the stomach) occurs in less than 1/30,000 cases.