1 Division of Gastroenterology, Department of Medicine, Stanford, Calif.
2 Division of Gastroenterology, Department of Medicine, Stanford, Calif; Gastroenterology Section, Veterans Affairs Palo Alto Health Care System, Palo Alto, Calif.
3 Tuberculosis Section, Division of Communicable Disease Control and Prevention, Alameda County Public Health Department, San Leandro, Calif.
4 Division of Digestive Diseases, Department of Medicine, Yale, Conn.