Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Gallstones ?
    ### Response:
    The biliary tract consists of the gallbladder and the bile ducts. The bile ducts carry bile and other digestive enzymes from the liver and pancreas to the duodenumthe fi rst part of the small intestine.
                
The liver produces bilea fl uid that carries toxins and waste products out of the body and helps the body digest fats and the fat-soluble vitamins A, D, E, and K.
    