Since I have suffered for thirty years of IBS I wonder what role foods play
in IBS. So I asked Dr Douglas Drossman at the UNC Center for Functional GI and
Motility disorders and here was his response. This is not a substitute for
seeking medical advise from your doctor on any specific conditions you may have,
but for educational purposes only.
Dr. Drossman is a Co-director of the Center and Professor of Medicine and
Psychiatry at UNC-CH. He established a program of research in functional
gastrointestinal disorders at UNC more than 15 years ago and has published more
than 250 books, articles, and abstracts relating to epidemiology, psychosocial
and quality of life assessment, design of treatment trials, and outcomes
research in gastrointestinal disorders.
Dr Drossman's comments on foods for IBS Health.
Shawn,
To say that people with IBS may get symptoms from food intolerances is an
acceptable possibility, since the gut will over react to stressors of all types
including food (high fat or large volumes of food in particular). Futhermore,
there can be specific intolerances. So if you have a lactose intolerance for
example, it can exacerbate, or even mimic IBS. Other examples of food substances
causing diarrhea would be high consumers of caffeine or alcohol which can
stimulate intestinal secretion or with the latter, pull water into the bowel
(osmotic diarrhea). The same would be true for overdoing certain poorly absorbed
sugars that can cause an osmotic type of diarrhea Sorbitol, found in sugarless
gum and sugar substituted foods can also produce such an osmotic diarrhea. Even
more naturally, people who consume a large amount of fruits, juices or other
processed foods enriched with fructose, can get diarrhea because it is not as
easily absorbed by the bowel and goes to the colon where it pulls in water. So
if you have IBS, all of these food items would make it worse.
However, it is important to separate factors that worsen IBS (e.g., foods as
above, stress, hormonal changes, etc.) from the cause or pathophysiology of IBS.
Just like stress doesn't cause IBS, (though it can make it worse), foods must be
understood as aggravating rather than etiological in nature.
The cause of IBS is yet to be determined. However, modern research
understands IBS as a disorder of increased reactivity of the bowel, visceral
hypersensitivity and dysfunction of the brain-gut axis. There are subgroups
being defined as well, including post-infectious IBS which can lead to IBS
symptoms. Other work using brain imaging shows that the pain regulation center
of the brain (cingulate cortex) can be impaired, as well as good evidence for
there being abnormalities in motility which can at least in part explain the
diarrhea and constipation. So finding a specific "cause" of IBS has grown out of
general interest in place of understanding physiological subgroups that may
become amenable to more specific treatments. Hope that helps.
Doug
