What is the characteristic symptom of biliary colic related to gallstones?

The characteristic symptom of biliary colic is typically due to the obstruction of the cystic duct by gallstones. When a gallstone temporarily obstructs the cystic duct, it can lead to a buildup of bile in the gallbladder, which can cause the gallbladder to distend and produce sharp, intermittent pain in the right upper quadrant of the abdomen. This type of pain is often referred to as biliary colic and is usually triggered by the consumption of fatty meals, which stimulate the gallbladder to contract, exacerbating the obstruction.

While other symptoms such as nausea and vomiting can accompany biliary colic due to the pain and the resulting stress on the gastrointestinal tract, they are not the defining characteristic. Steatorrhea, which indicates malabsorption of fats, is more commonly associated with chronic conditions affecting the bile or pancreatic function rather than acute biliary colic. Abdominal tenderness may be present upon examination but is not as specific to biliary colic as the symptoms associated with cystic duct obstruction. Thus, the blockage of the cystic duct by gallstones specifically explains the hallmark symptom of biliary colic.