Dr. Dtewart W. Buch, 55, an associate clinical professor of medicine at George Washington University Medical School and cofounder of the Arthritis Clinic of Northern Virginia, died July 22 at his home in Great Falls, Va., after a heart attack.

Born in Holyoke, Mass. Dr. Bush graduated from the University of Massachusetts in 1943 and three years later received his M.D. from Johns Hopkins Medial School.

Following a nine-month internship at Bellevue Hospital in New York City, he entered the Army Medical Corps. After two years in Europe, he was discharged with the rank of captain.

From 1949 to 1951 Dr. Bush did his residency training at George Washington University Hospital, and in 1952, he joined the teaching staff at the universitys' medical school. In 1970, while retaining his tenure at GWU, Dr. Bush and two colleagues opened the arthritis clinic in Arlington.

Dr. Bush was a member of the American Medical Association, the Society of Internal Medicine the Medical Societies of Washington, Arlington County, and Virginia, the Arthrities and Rheumatism Association, and the Rheumatism Society of Washington.

He was also a staff doctor and member of the board of the Arthritis Institute of the National Orthopaedic and Rehabilitation Hospital in Arlington.

Surviving are his wife, Priscilla B., and his daughter, Karen, both of the home; and his mother, Mary Bush of Holyoke, Mass.

The family requests that expressions sympathy be sent to the Kidney Foundation, 1825 Connecticut Ave., NW.