colchicine, drug used in the treatment of gout, a disease that is characterized by severe inflammation in one or more of the joints of the extremities. Colchicine is obtained from the autumn crocus (Colchicum autumnale). The mechanism by which colchicine relieves the pain of gout, which is caused by solid deposits of uric acid in the joints, the kidneys, and other tissues, is unknown. Side effects include diarrhea and other gastrointestinal disturbances.