Cholelithiasis (or gallstones) are solid small objects that originated in the gallbladder and it is a very common condition. There are three main types of gallstones can be studied separately in the literature: Cholesterol stones, pigment stones, and mixed stones.

There is uncertainty regarding the real causes behind the formation of gallstones. However, physicians may regard the formation of gallstones to too much cholesterol in the bile, too much bilirubin in the bile, or problem in gallbladder draining. There are many factors, which can contribute to increasing the possibility of having gallstones such as overweight or obesity, being female, being sedentary, and high fat /cholesterol foods intake.

Supersaturation is recognized to be the main mechanism underlying the formation of gallstones when constituents surpass their maximum solubilities in bile.Other additional factors that may play a role in gallstone formation are nucleation factors, calcium in bile, and bile stasis within the gallbladder. Symptoms are rare in most cases of gallstones. However, sudden, severe abdominal pain, known as biliary colic can be manifested once a gallstone blocks one of the bile ducts. Other symptoms may include fever, rapid heartbeat, yellowing of the skin and whites of the eyes (jaundice), and loss of desire to eat.

Several tests and procedures commonly used to diagnose gallstones may include creating pictures of the gallbladder by using ultrasound and a computerized tomography (CT) scan, checking the bile ducts for gallstones by Hepatobiliary iminodiacetic acid (HIDA) scan and magnetic resonance imaging (MRI), and blood tests that may help detect the presence of jaundice, infection, pancreatitis or other certain complications associated with gallstones. Treatment options for gallstones mainly include surgery (to remove gallbladder) and medications to dissolve the gallstones.

Complications of gallstones may include cholecystitis (inflammation of the gallbladder), blockage of the common bile duct, blockage of the pancreatic duct, gallbladder cancer, and gallstone ileus. Though the studies still immature, changes to the diet and losing weight may be recommended to prevent gallstones. It is very rare for the asymptomatic gallstones to lead to any significant problems. Death is very rare even for symptomatic gallstones.

According to a study published in the journal of hepatology, gallstones or cholelithiasis are a major public health concern in Europe and other developed countries and affect up to 20% of the population.Also, about 80% of gallstones carriers are diagnosed without appearing symptoms. However, the incidence of gallstones increases with age and it is higher in women than in men.

Cholelithiasis (or gallstones) are solid particles that originated in the gallbladder and it is a very common condition in the population. Gallstones vary in size and dimension.It sometimes can take the size of a golf ball. Sudden pain in the upper right abdomen can be caused by the formation of gallstones. Gallbladder attack or biliary colic are the names that given to this pain and this pain appear when gallstones narrow the ducts of the biliary tract. Some people are vulnerable to develop just one gallstone, while many gallstones can be found at the same time in many people.

There are three main types of gallstones that can be studied separately in the literature:

• Cholesterol stones: Mostly, these stones are made up of hardened cholesterol and usually they appear yellow-green colored. It accounts for more than 80 % of gallstones.
• Pigment stones: Usually appeared as dark-colored stones and they formed by bilirubin. About 15-20% of all biliary stones are pigment stones.
• Mixed stones: These stones are made up of calcium salts, pigment, and cholesterol and they are faceted. About 10% of these stones are opaque to one or another form of radiation, such as X-rays.

There is uncertainty in the medical literature regarding the real causes behind the formation of gallstones. Healthcare providers may consider the following causes of gallstones:

• There is too much cholesterol in the bile: In the usual circumstances, enough chemicals exist in the bile to dissolve the cholesterol excreted by the liver. However, cholesterol may form into crystals or stones when the liver keeps excreting more cholesterol than bile can dissolve.
• There is too much bilirubin in the bile: Bilirubin functioning when the body recycling red blood cells. Too much bilirubin can be excreted by the liver in certain conditions including liver cirrhosis, certain blood disorders, and biliary tract infections. Gallstone formation can be enhanced by the excessive amount of bilirubin.
• A problem in gallbladder draining: If the gallbladder facing problem in empty completely or often enough, gallstones could be formed by the sluggish concentrated bile.

There are many factors which can increase the possibility of having gallstones. The followings are some of those factors according to various studies:

• Being overweight, obese, or pregnant (if woman).
• Being female, because gallstones are more common in females.
• Being sedentary or lack of physical activity.
• High-fat foods /cholesterol foods intake.
• Low-fiber foods intake.
• Being age 40 or older.
• A family history of previous gallstones cases.
• Having diabetes or liver disease.
• Losing weight very quickly, because of probable accumulation resulted from sudden metabolism transformations.
• Consuming drugs that contain estrogens, such as oral contraceptives or hormone therapy drugs.
• Being a Native American or Mexican-American.

Cholelithiasis is the process when gallstone formed in the gallbladder (biliary vesicle). It is known to happen in a slow pace, and most of the time it generates no pain or other certain symptoms. In general, most of gallstones are either the cholesterol or mixed type. There is variation in gallstones size. Some of these stones can range from millimeters to several centimeters. Supersaturation is recognized to be the main mechanism underlying the formation of gallstones when constituents surpass their maximum solubilities in bile. Other additional factors that may play a role in gallstone formation are nucleation factors, calcium in bile, and bile stasis within the gallbladder.

Cholesterol is the major substance,  forming about 70% of gallstones. Another type named pigment stones (black or brown) is also very common and encompass the remaining 30% of stones. In addition, a mixture of the two gallstone types can be observed in many cases.

• Cholesterol Stones: Despite the fact that cholesterol forms merely 5% of bile contents, the majority of gallstones cases found in the American population are formed from cholesterol. The typical process of forming cholesterol gallstones can be described in the following: In order to cholesterol to remain suspended in the fluid, it is transported within micelles (clusters of bile salts) because cholesterol is poorly soluble. The bile fluid turns to sludge once an imbalance between these bile salts and cholesterol occur. The resulted thickened fluid consists of a mucus gel that has cholesterol and calcium bilirubinate. The mentioned imbalance can reach to a more critical point until it makes up cholesterol crystals by supersaturation mechanism which lead to gallstones as a final outcome.
• Pigment Stones: Pigment stones are made up of calcium bilirubinate. Pigment stones come in two common colors: Black and brown. People with hemolytic anemia or cirrhosis are more vulnerable to develop black stones.Brown stones contain more cholesterol and calcium than black stones and are more likely to form in the bile ducts. Black stones are more common than brown stones. Infection is known to contribute to the development of these stones.
• Mixed stones: Mixed stones are a mixture of cholesterol and pigment stones.

Symptoms are rare in most cases of gallstones. However, sudden, severe abdominal pain, known as biliary colic can be manifested once a gallstone blocks one of the bile ducts. The pain generated by gallstones can be triggered sometimes by eating fatty foods, but may occur at any time of day and may be mistaken for a heart attack or a peptic ulcer. More critical problems can occur in case the gallstones block the flow of bile for longer periods or move into other organs such as the pancreas or small bowel. If someone reaches  this stage, one of the following signs and symptoms may appear:

• Persistent pain
• Fever with temperature above 38C (100.4F)
• Rapid heartbeat and mental confusion
• Yellowing of the skin and whites of the eyes (jaundice)
• Loss of desire to eat
• Itchy skin
• Watery stool
• Chills or tremor attacks

Around 60-80% of gallstone cases remain asymptomatic throughout a one’s lifetime and could be discovered by a pure chance when imaging tests are conducted to uncover other health issues.  The remaining 20-40% of gallstones cases are either symptomatic or asymptomatic with the development of complications.

Some of the tests and procedures that commonly used to diagnose gallstones could include:

• Creating pictures of the gallbladder: An abdominal ultrasound and a computerized tomography (CT) scan could be suggested by physicians to create pictures of the gallbladder. The most preferred diagnostic procedure to evaluate right upper quadrant pain is ultrasound test.
• Checking the bile ducts for gallstones: The evaluating of bile ducts condition can be performed by a test that uses a special dye to highlight the bile ducts on images to provide the healthcare provider with a helpful hint to determine whether a gallstone is causing a blockage or not. Some of the tests that may involve in the process are: Hepatobiliary iminodiacetic acid (HIDA) scan, which is an imaging technique used to diagnose problems of the liver; gallbladder; and bile ducts, magnetic resonance imaging (MRI) which is widely known medical imaging technique, and endoscopic retrograde cholangiopancreatography (ERCP) which uses a dye to mark the bile ducts on X-ray images. Gallstones discovered using ERCP could be removed during the procedure.
• Blood testing: Blood tests may detect abnormalities related to the presence of jaundice, infection, pancreatitis or other certain complications associated with gallstones.

Treatment options for gallstones mainly include surgery and medications:

• Cholecystectomy: If the gallstones frequently recur, the physician may suggest surgery to remove the gallbladder. Without being stored in the gallbladder, the bile will flows directly from the liver into the small intestine once gallbladder removed from the body. The human being can live without a gallbladder, also, food digestion will not be affected by gallbladder removal, but the removal may cause usual temporary diarrhea.
• Medications: Oral medications can be prescribed to help in dissolving the gallstones. However, sometimes medications do not work and probably the gallstone will form again and if not, it may take months or years of prescribing medications to dissolve the gallstones completely. However, it is uncommon to use medications for gallstones, medications are prescribed for people who unable to go through the surgery. Ursodiol (actigall) is used in such conditions.

Complications of gallstones may include:

• Cholecystitis (inflammation of the gallbladder): Cholecystitis which can cause severe pain and high temperature can result from a gallstone that built up in the neck of the gallbladder.
• Blockage of the common bile duct: This blockage can cause jaundice and bile duct infection, all which resulted from gallstones that block the tubes (ducts) through which bile flows from the gallbladder or liver to the small intestine.
• Blockage of the pancreatic duct: This blockage in the pancreatic duct can lead to pancreatitis (inflammation of the pancreas). Pancreatitis usually requires hospitalization and cause intense, constant abdominal pain.
• Gallbladder cancer: Gallbladder cancer is a very rare condition.People with a previous history of gallstones have an increased risk of gallbladder cancer but the likelihood is small in general.
• Gallstone ileus: The condition when gallstones enter the intestinal tract after the formation of a fistula between a gangrenous gallbladder and the bowel wall (typically the duodenum).

Based on the limited evidence based-studies that available regarding prevention of gallstones, changes to the diet and losing weight may help prevent gallstones:

• Diet: It is recommended to change the habit of eating too many foods with a high saturated fat content because of the clear role of cholesterol in the formation of gallstones.Foods such as cakes and biscuits, meat pies, sausages and fatty cuts of meat etc. In addition, there is evidence that suggests eating nuts, such as peanuts or cashews, can help reduce the risk of getting gallstones. 
• Losing weight: Increasing the amount of cholesterol in the bile by being overweight or obese can contribute to a higher risk of getting gallstones.

Surgery can easily treat most cases of gallstone disease. Life-threatening conditions only exist in very critical cases especially in people who suffer already from poor health status.

It is very rare for the asymptomatic gallstones to lead to any significant problems. Death is very rare even for symptomatic gallstones. Critical complications are also rare. However, in case they occur, stones in the bile duct or surgery are the possible sources of the complications. Symptoms do not appear again in nearly all people who have gallbladder surgery.

• According to a study published in the Swiss journal of hepatology, gallstones or cholelithiasis are a major public health concern in Europe and other developed countries and affect up to 20% of the population.
• About 80% of gallstones carriers are diagnosed without appearing symptoms.
• The incidence of gallstones increases with age and it is higher in women than in men.
• Cholelithiasis (or gallstones) represents one of the most common surgical concerns worldwide and is particularly prevalent in most western countries.
•  According to a study published in Gastroenterology Research and Practice journal, Common bile duct stones found in 3-14.7% of all patients for whom gallbladder removal is performed.
• Gallstones are most common among older adults, women, overweight people, Native Americans and Mexican Americans.