What Causes Gallstones in Children?

Gallstones are hardened accumulations of chemicals in the gallbladder. They form through a process called cholelithiasis, and generally range from a few millimeters to a few centimeters in diameter, notes the University of Maryland Medical Center, or UMMC. While the exact causes of gallstones are unknown, there are risk factors associated with their development. Gallstones are not uncommon in adults, affecting about 25 million in the United States annually, but they are fairly rare in children.

Types

Most gallstones are made up predominantly of cholesterol, calcium carbonate or pigment called calcium bilirubinate. The rates of occurrence are different in children than in adults, as the study "Calcium Carbonate Gallstones in Children" found. While cholesterol stones make up around 75 percent of adult stones, they account for less than 25 percent in children. Pigment stones, the second most-common type in adults and children, account for around 15 and 20 percent, respectively. Calcium carbonate stones are rare in adults, accounting for only about 4 percent of stones. This type is significantly more common in children, accounting for about 25 percent of childhood gallstones. Around 5 percent of children have protein gallstones.

Risk Factors

Although adult women are far more likely to develop gallstones than adult men, occurrence in children is about equal, notes UMMC. Obesity, congenital blood disorders such as spherocytosis or sickle cell disease and a family history of gallstones put a child at increased risk of developing the condition, according to Seattle Children's Hospital, or SCH. A high-fat, high-cholesterol or low-fiber diet increases risk as well, explains MayoClinic.com.

The gallbladder is a small organ that stores bile until the body is ready to use it for digestion. When bile is needed, the gallbladder releases it into the intestine. Bile is produced by the liver and helps with fat digestion. It is made up of water, fats, salts, proteins, bilirubin and cholesterol. Gallstones generally form when the cholesterol hardens, but gallstones can also form from hardened bilirubin. Gallstones are more common in adults, but children also sometimes get gallstones. Usually, children who develop gallstones have no specific reason or underlying condition responsible for the gallstone formations; however, several factors and conditions increase the risk of gallstone formations in children. In addition, those children who have parents who have had gallstones are more likely to develop gallstones themselves.

Symptoms

Some gallstones produce no symptoms, but when they do, symptoms are usually sudden, says SCH. Pain in the upper right or middle right section of a child's abdomen or back is a primary symptom of gallstones, according to Children's Hospital Boston. The pain, which also sometimes manifests between the shoulder blades or in the right shoulder, usually lasts about half an hour, and often presents after eating, especially following fatty or greasy meals. Gallstones that obstruct a child's bile duct may also cause nausea, vomiting, fever and jaundice, adds SCH.