Two of the most common diseases which they need to treat are hepatitis, inflammation of the liver caused by viral infections or medication, and liver cirrhosis, which is usually related to alcoholism.

There are three kinds of hepatitis, Hepatitis A, B and C. Hepatitis C was only discovered recently and was previously known as Non-A or Non-B Hepatitis. Symptoms of this disease include fatigue, lethargy, jaundice (yellow pigmentation of the skin which is found in all three types of hepatitis), itching, abdominal pain and fever.

It is transmitted via the blood but there can also be a very slow rate of sexual transmission. Blood for transfusion purposes is always screened for Hepatitis-C, as for HIV, before being used.

All three forms of Hepatitis can be treated, but if not dealt with in time, they can cause cirrhosis and permanent scarring of the liver. 

Gastroenterologists are qualified to perform endoscopies, which enable the visualisation of the internal organs through the use of a flexible instrument inserted through the mouth or rectum.

An endoscope utilises a video chip and strobe light to capture an image which is then displayed on a video monitor. This allows inspection of the entire inner surface of the organ being examined.

This procedure is mainly used to diagnose abdominal pain and bleeding which are usually caused by inflammation within the stomach, ulcers or heartburn. This type of inspection of the lower digestive tract is called a colonoscopy and is frequently utilised to remove polyps (small growths) that may become cancerous over time.

Other diseases treated by gastroenterologists are diarrhoea, ulcers, colitis, constipation, lactose intolerance, gallstones and heartburn, etc.