About Mark

Mark H. Johnston, M.D., currently works in a private gastroenterology practice in Lancaster, Pennsylvania. He is a retired U.S. Navy Captain and former head of Gastroenterology at the National Naval Medical Center in Bethesda, Maryland, where he served as a gastroenterology consultant to the White House, U.S. Congress, and the Supreme Court during the 1990's. 
 

Dr. Johnston, who earned a Doctor of Medicine degree from Hahnemann University in Philadelphia, holds two U.S. patents in GI research and is the inventor of endoscopic cryospray ablation using liquid nitrogen.

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He has received numerous military, academic, research, and humanitarian awards for his service and participated in multiple short-term medical mission trips to Albania, Kenya, and China.

Additionally, Mark is the founder and president of the Johnston’s Hope Foundation, a 501(c)(3) charity dedicated to supporting Christian missions globally. Through this foundation, Dr. Johnston has enabled funding for many ministries, including medical missions and educational programs, primarily in Albania.

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Mark and his wife, Lavonne, have been married for more than forty years, and their three adult children have all chosen careers in medicine and surgery.

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Together, Mark and Lavonne have hiked in dozens of national parks in the U.S. and Canada. In 2022, Mark made a solo trek on the Camino Frances, a 540 mile spiritual pilgrimage from Saint-Jean-Pied-de-Port in southern France to Santiago, Spain.

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17 Cairns is his first book.