What Are Gallstones?

Gallstones comprise cholesterol stones, pigment stones and ‘mixed stones’, which are stones comprising different ratios of pigment and cholesterol. Photo: Wikimedia Commons

The gallbladder is a pear-shaped organ intimately related to the liver and the digestive tract in form and function.

It serves as a reservoir of bile, which is a vital body fluid produced in the liver and flows through the bile ducts to the intestines.

As bile is continuously secreted, excess bile flows passively into the gallbladder. At variable intervals – usually when food is ingested – the gallbladder actively contracts to squirt its contents into the intestines through the bile ducts.

Gallstones are tricky customers. Certainly, not all gallstones are the same. Scientifically, they comprise cholesterol stones, pigment stones and “mixed stones”, which are really what they sound like, i.e. stones comprising different ratios of pigment and cholesterol.

Pure pigment stones are rare. Cholesterol stones, however, are very common. They make up the vast majority of gallstones and are responsible for the largest share of the problem.

As such, let me limit this discussion to these stones.

Cholesterol is essential to life. In the human body, it is produced in cells. Ingested cholesterol, from eating meat or animal products such as butter, cheese and lard, is also absorbed into the body.

Excess cholesterol is excreted in a complex manner, but mostly by the liver cells through bile.

Cholesterol is dissolved in bile and is further concentrated in the gallbladder by the absorption of water. The longer bile is retained in the gallbladder, the more concentrated it becomes.

The gallbladder empties itself under the influence of hormones such as cholecystokinin and secretin, which are released on the ingestion of foods.

Due to factors that are still not clear, for some people, the process of gallbladder contraction becomes inefficient over time. This leads to the stagnation of bile, which then becomes too viscid, leading to the formation of cholesterol particles.

Eventually, these particles coalesce to form stones. As such, it is the diseased gallbladder that gives rise to gallstones.

While this is true, there is no doubt that many underlying factors predispose to gallstone formation and conspire to provide the ideal environment for this phenomenon.

Obesity, a diet rich in animal products (which include not just meat and poultry, but dairy products and lard as well), hormonal changes in women as they approach menopause, crash diets and excessive vitamin supplementation, among others, have been implicated in the formation of gallstones.