Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Hydrogen breath testing is used in the
diagnosis of three conditions.
The first is a condition in which dietary sugars are not digested
normally. The most common sugar that is poorly digested is
lactose, the sugar in
milk. Individuals who are unable to properly digest lactose are referred to
as lactose intolerant.
Testing also may be used to diagnose problems with the digestion of other
sugars such as sucrose,
fructose and sorbitol.
The second condition for which hydrogen breath testing is used is for
diagnosing bacterial overgrowth of the small bowel, a condition in which
larger-than-normal numbers of colonic bacteria are present in the small
The third condition for which hydrogen breath testing is used is for
diagnosing rapid passage of food through the small intestine. All three of
these conditions may cause
abdominal pain, abdominal
bloating and distention,
flatulence (passing gas in large amounts), and