Which condition is characterized by solid, round stones that may go unnoticed until fatty food consumption?

The condition characterized by solid, round stones that may go unnoticed until fatty food consumption is cholelithiasis. This condition involves the formation of gallstones within the gallbladder, which can vary in size and number. The presence of gallstones can remain asymptomatic until certain triggers, such as the ingestion of fatty foods, provoke symptoms. When fatty foods are consumed, the gallbladder is stimulated to contract to help digest the fats, but if gallstones are present, this contraction can lead to obstruction or inflammation, resulting in pain and other symptoms.

Cholecystitis is related but specifically refers to the inflammation of the gallbladder that can occur when a gallstone obstructs the bile ducts. Hepatitis B is a viral infection that affects the liver and does not involve gallstones, while pancreatitis is the inflammation of the pancreas, typically due to factors such as gallstones but not primarily characterized by the presence of gallstones themselves. Cholelithiasis directly describes the condition of having gallstones, making it the most accurate answer to the question posed.