Dear Dr. Roach: A few years ago, I was diagnosed with ischemic colitis after running a half-marathon. My doctor advised me not to run more than 15 kilometres at a time. Since then, I have had a return of symptoms, such as bloody diarrhea, if I run for longer than an hour. I have kept my running times under that with no problems.
This summer, I went on a 300-km hiking holiday, which included some strenuous hill climbing. I did have some cramping and bloody diarrhea during the trip.
At this point, I wonder if I should get any tests done to look for blockages. I am 65 and willing to give up the marathons, but not the walking.
L.M.R.
Ischemic colitis (”ischemic” means “holding back of blood,” colitis is inflammation of the colon) is a not-uncommon condition, most often affecting those over 65, but also in younger individuals, especially young women taking estrogen. Ninety-five per cent of the time, there are no blockages and the symptoms are due to a temporary decrease in blood flow to the colon, especially those areas farthest away from the arteries supplying blood (called watershed areas). This condition is very different from the life-threatening acute mesenteric ischemia, in which a blockage of the small or large bowel causes infarction (death) of a part of the gut.
I normally see mesenteric ischemia in people with some risk factors, such as heart failure or hemodialysis. It can, however, occur in healthy older people. Exercise-induced mesenteric ischemia is well-described, and it happens in marathoners and other endurance athletes. Part of the body’s response to prolonged exercise is to preferentially send blood to the heart and muscles, away from the gut and kidneys. It is thought that this happens to an increased extent in people who get exercise-induced mesenteric ischemia.
Since it is so rarely associated with blockages, I don’t think tests would be likely to yield anything. However, I certainly would recommend that you do what you can during exercise to minimize this happening again, since very rarely surgery is necessary. Specifically, I would make sure you don’t get depleted of salt and water, taking plenty of fluids, perhaps sports drinks, to make sure your sodium and potassium levels stay normal. I also would take it easier when on strenuous hikes, and rest a bit more.
Dear Dr. Roach: Regarding your advice on breast cancer prevention, the Institute of Medicine published a comprehensive book in 2011 titled Breast Cancer and the Environment: A Life Course Approach.
It noted: “… evidence suggests that women may have some opportunities to reduce their risk of breast cancer through personal actions: avoiding unnecessary medical radiation throughout life, avoiding use of some forms of postmenopausal hormone therapy, avoiding smoking, limiting alcohol consumption, increasing physical activity and, for postmenopausal breast cancer, minimizing weight gain.”
I would make note that two of the top three items listed are actually dispensed or administered by physicians or other providers.
M.N.
Thank you for this information. All of these make sense, but let me clarify two issues. The first is that while unnecessary radiation is surely to be avoided, there are some times when medical radiation is necessary, and that most radiologic procedures, such as chest X-ray and mammograms, have very small doses of radiation, equivalent to less than a day’s worth of the radiation that we are all exposed to continuously. The second is that the postmenopausal hormone therapy most closely associated with increased breast cancer risk is combination estrogen and medroxyprogesterone.
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