Doc: IBS symptoms on hiatus following colonoscopy

Keith Roach
To Your Health

Dear Dr. Roach: I have suffered for several years now from irritable bowel syndrome. I believe my symptoms began after back-to-back bouts of food poisoning, possibly norovirus. That said, I noticed something curious, and a gastroenterologist said that while it was not uncommon, he could offer no explanation. I thought maybe you might have a theory.

I’ve noticed that following a colonoscopy, my bowel movements returned to “normal” in accordance with the Bristol stool chart, and those normal bowel movements continued for anywhere between a month and six weeks before the IBS symptoms returned.

Do you think the process of prepping for colonoscopy removes an excess of bacteria from your colon? If so, would this indicate that IBS may be related to an overgrowth of bacteria? One thing I should add is that in my case, everything remained consistent with respect to diet before the colonoscopy prep and the diet after the colonoscopy.


Dear K: I often have heard that the pattern of bowel movements changes in some people after a colonoscopy. My experience is that it worsens symptoms at least as often as it helps them. It is clear that the bacteria count in the gut drops dramatically (31-fold) after the preparation, and that the types of bacteria in the gut change in the weeks following a colonoscopy.

I suspect that it isn’t the total number of bacteria, but rather their type that has the greater effect on bowel movements. Several small studies on probiotics (healthy bacteria) in people with IBS have shown some benefit, but others have not.

Since you notice significant benefit with colonoscopy prep, it leads me to hypothesize that you might benefit from probiotics. I would recommend that you discuss this with your gastroenterologist.

Dear Dr. Roach: Can you write about Addison’s disease?


Dear D.L.: Addison’s disease is an autoimmune condition where the body destroys the cells in the adrenal gland, which is responsible for making cortisone. Cortisone is important for many of the body’s functions. Early on, the symptoms of cortisone deficiency are subtle — fatigue, lightheadedness, low blood pressure.

Too-low levels of cortisone can cause what is called an Addisonian crisis during times of stress. Very low blood pressure, vomiting and diarrhea, fever and confusion are common signs. This is an emergency and needs to be treated with cortisone right away.

There are few treatments in medicine as effective as giving cortisone to someone with an Addisonian crisis — it’s like watching someone come back to life.

Fortunately, Addison’s disease is rare. It is most commonly diagnosed with a blood test, or by stimulating the adrenal gland with a hormone (ACTH) to see if cortisol levels in the blood go up. People with Addison’s disease need replacement cortisone every day to prevent problems.

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