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James Christensen, MD

By: Celine Robins

Dr. James Christensen

Award for Achievement

James Christensen (64R–­­gastroenterology) is an internationally recognized physician, scholar, and scientist responsible for major contributions to the understanding and management of gastrointestinal tract diseases. He provided the first explanation of the motions of the human esophagus in swallowing, proved the existence of the lower esophageal sphincter, and discovered the pacemaker cells of the colon. Christensen became the first director of the Division of Gastroenterology in the Carver College of Medicine in 1971, serving there for 17 years and concurrently as the director of the division’s National Institutes of Health academic training program. Christensen received the Janssen Award for Lifetime Achievement in Gastrointestinal Motility from the American Gastroenterological Association in 1997. He has been a University of Iowa professor emeritus of internal medicine since his retirement in 1998.

In 1966, Christensen was appointed to his first faculty position in the Carver College of Medicine. He has fond memories of what was called “the doctors’ round table" during that time: a small cross-departmental group of faculty members who lunched together in the hospital cafeteria and discussed medical matters, current affairs, and other topics of common intellectual interest. 

“At Ernie Theilen’s funeral, the pastor read a letter Ernie wrote on his deathbed bidding a special farewell to his friends from the round table,” says Christensen. “It was that kind of place." 

Prior to Christensen’s description and characterization of the lower esophageal sphincter in 1969, it was not fully understood how material in the stomach was kept from re-entering the esophagus.

“Our ignorance was due to the fact that we had no appropriate animal model to study,” he says. “I found one, and so I was able to define the mechanisms that operate to control the esophagus.”


His pioneering experiments on that animal model, the opossum, opened new avenues of discovery in the description and treatment of esophageal diseases like ulceration, acid reflux, stricture, and cancer.  

He also discovered the pacemakers that govern motility in the mammalian colon and described their operation, basic studies which have now been carried further elsewhere. His collaboration with Professor Enzo Macagno of the Hydraulics Institute on the fluid mechanics of gastrointestinal flow led to advances in the understanding of disordered defecation. 

He wrote or provided principal authorship of more than 250 papers, reviews, book chapters, and editorials. He wrote, co-authored, and edited five books on matters related to his research and to clinical gastroenterology and one book on chamber music for stringed instruments. He advised or served on the editorial boards of many professional journals and was invited to lecture throughout the U.S. and in Europe, Australia, South America, and Asia. 

Christensen’s advice to current Carver College of Medicine students is simple: Follow your interests. 

“I never set a specific long-term career goal for myself. I made all career choices simply based on what seemed most interesting,” he says.  

In his retirement, he has continued to follow his interests in gardening and orchestral music, the latter as a lifelong cellist.