About. Digestive Disease and Endoscopy Center, PLLC is a licensed and registered Gastroenterology specialty center. Dr. Pankaj Sharma founded our practice in 1982, the first board certified gastroenterologist to practice in Kitsap, Jefferson, and Mason Counties. Dr. Yuen San Yee joined the practice in 1991 and Dr. Narendra Siddaiah joined in 2009..