From an underlying abnormal excess of the mineral, e.g., with elevated levels of calcium (hypercalcaemia) that may cause kidney stones, dietary factors for gallstones. Local conditions at the site in question that promote their formation, e.g., local bacteria action (in kidney stones) or slower fluid flow rates, a possible explanation of the majority of salivary duct calculus occurring in the submandibular salivary gland. Enteroliths are a type of calculus found in the intestines of animals (mostly ruminants) and humans, and may be composed of inorganic or organic constituents.