Gallstones form when cholesterol in bile crystallises out of solution to form stones. Following their formation, gallstones gradually grow in size and number and may cause disruption of the flow of bile from the gallbladder into the duct system.

Bile is a secretion produced by the liver to aid digestion of fats. Its solubility is dependent on the correct balance between cholesterol, bile acids, phosphatidyl choline and water.

Likely symptoms which indicate gallstone formation include nausea, vomiting, severe abdominal pain, bloating and discomfort following a heavy, fatty meal.

Conventional treatment of gallstones consists of using gallstone-dissolving drugs or surgery. Where this is inappropriate removal of the gallbladder may be considered.

Gallstones are largely attributed to the western diet, due to a low intake of dietary fibre and highly refined foods. This leads to a reduction in bile acid levels, which are essential for maintaining the solubility of cholesterol. Treatment is therefore best aimed at reducing those factors that contribute to the formation of gallstones.

Increased intake of both soluble and insoluble fibre, which includes vegetables, nuts, pectin has been found to decrease the formation of deoxycholic, which increases the solubility of cholesterol, by promoting its excretion through faeces.

A diet comprising of high fibre such as found in a vegetarian diet has been shown to offer a protective factor against gallstone formation.