Mark A. Korsten, MD
Associate Chief of Graduate Medical Education
Program Director, Internal Medicine Residency Program
Chief of Gastroenterology
James J. Peters VA Medical Center
Professor of Medicine
Mt. Sinai School of Medicine (718) 584-9000 ext 6709
In 1966, Dr. Mark A. Korsten received his B.A. from Yale College and in 1970, he received his M.D. from Yale School of Medicine. Dr. Korsten is board certified in Internal Medicine and Gastroenterology. In his early years in medical investigation, he focused his studies on the effects of alcohol on the pancreas, but, his focus turned to the problems of bowel care in Veterans with spinal cord injury. Because of the severe life-altering impact of bowel dysfunction on persons with spinal cord injury and that there had been no, or very little, progress in this field for many years, Dr. Korsten wanted to reshape the treatment and find better approaches through scientific study.
For the past forty years, Dr. Korsten has been associated with the James J. Peters Veterans Affairs Medical Center. He has been the Director of the VA’s Internal Medicine Residency Program, which is associated with the Icahn School of Medicine at Mount Sinai, since 1991. Since the mid-1990s, Dr. Korsten has been Professor of Medicine and Chief of Gastroenterology of the James J. Peters Veterans Affairs Medical Center.
Since the start of his association with the Spinal Cord Damage Research Center, Dr. Korsten has enjoyed collaborating with scientists in several diverse fields of study. This multidisciplinary interaction allowed the invaluable sharing of ideas and techniques. Dr. Korsten has over 100 peer-reviewed publications in gastroenterology, spinal cord medicine, and pharmacological interventions to improve bowel function in spinal cord injury. He and Dr. Bauman have developed a new, safe approach for bowel care by using a medication, neostigmine. The objective of the research performed by Dr. Korsten and his team is to improve care to Veterans with spinal cord injury and by doing so, to ensure a better quality of life and improved health.
Program goals (Lay)
Digestion is the manner by which the body absorbs nutrients from the gut from foods consumed. The digestive process is primarily under subconscious control. For persons with spinal cord injury who are sitting in a wheelchair most of their wakeful day, the bowel slows down, resulting in constipation and occasional, but incredibly embarrassing, stool incontinence.
Because of a lack of communication between the brain and the rectal muscles, persons with more complete forms of spinal cord injury have little to no control of the sphincter muscles that control having a bowel movement. In most cases, there is no conscious urge to have a bowel movement because messages from the gut cannot reach the brain. There may also be speculated to be a higher risk of colon cancer because of the slower rate at which stool moves through the large bowel.
Dr. Korsten and colleagues seek to improve bowel care by administering medications that safely and effectively cause bowel evacuation. To gain a better understanding of the changes in the movement of stool through the colon, high-resolution technology is being employed. Dr. Korsten is testing the use of biofeedback in persons with incomplete spinal cord injury to help improve rectal control that has been lost.
Program goals (Scientific)
The GI program is directed toward the bowel complications of spinal cord injury. Of these, difficulty with evacuation (constipation, incontinence and fecal impaction) is one of the most important quality of life problems in people with spinal cord injury. Bowel care is unpleasant, often ineffective and extremely time consuming. For a number of years, Dr. Korsten has been exploring the use of a specific prokinetic agent called neostigmine to improve bowel function. Under his supervision, neostigmine has been shown to result in a predictable, timely and complete bowel evacuation after intravenous administration. Although effective, the current intravenous or intramuscular method of administration of neostigmine is impractical for long-term use. As an alternative approach, Drs. Korsten and Bauman have recently demonstrated that the neostigmine can be delivered through the skin by a method called iontophoresis, which, in a dose dependent fashion, results in a bowel movement in the majority of subjects. More information about the current GI studies may be found at clinicaltrials.gov NCT02370433, NCT02406859, NCT02370862.