Irritable Bowel Syndrome Message Boards | Re: SHAWNERIC Re: WebMD: IBS/Fruct & SOME OTHER ?'s MAINLY ABT. BACTERIAL OVERGROWTH/Tests, etc.

Marnie, just fyi on this also you might want to see.

History of Functional Disorders

"Motility

In healthy subjects, stress can increase motility in the esophagus, stomach, small and large intestine and colon. Abnormal motility can generate a variety of GI symptoms including vomiting, diarrhea, constipation, acute abdominal pain, and fecal incontinence. Functional GI patients have even greater increased motility in response to stressors in comparison to normal subjects. While abnormal motility plays a vital role in understanding many of the functional GI disorders and their symptoms, it is not sufficient to explain reports of chronic or recurrent abdominal pain.

Visceral Hypersensitivity

Visceral hypersensitivity helps to account for disorders associated with chronic or recurrent pain, which are not well correlated with changes in gastrointestinal motility, and in some cases, where motility disturbances do not exist. Patients suffering from visceral hypersensitivity have a lower pain threshold with balloon distension of the bowel or have increased sensitivity to even normal intestinal function. Additionally, there may be an increased or unusual area of somatic referral of visceral pain. Recently it has been concluded that visceral hypersensitivity may be induced in response to rectal or colonic distension in normal subjects, and to a greater degree, in persons with IBS. Therefore, it is possible that the pain of functional GI disorders may relate to sensitization resulting from chronic abnormal motor hyperactivity, GI infection, or trauma/injury to the viscera.

Brain-Gut Axis

The concept of brain-gut interactions brings together observations relating to motility and visceral hypersensitivity and their modulation by psychosocial factors. By integrating intestinal and CNS central nervous system activity, the brain-gut axis explains the symptoms relating to functional GI disorders. In other words, senses such as vision and smell, as well as enteroceptive information (i.e. emotion and thought) have the capability to affect gastrointestinal sensation, motility, secretion, and inflammation. Conversely, viscerotopic effects reciprocally affect central pain perception, mood, and behavior. For example, spontaneously induced contractions of the colon in rats leads to activation of the locus coeruleus in the pons, an area closely connected to pain and emotional centers in the brain. Jointly, the increased arousal or anxiety is associated with a decrease in the frequency of MMC activity of the small bowel possibly mediated by stress hormones in the brain. Based on these observations, it is no longer rational to try to discriminate whether physiological or psychological factors produce pain or other bowel symptoms. Instead, the Functional GI disorders are understood in terms of dysregulation of brain-gut function, and the task is to determine to what degree each is remediable. Therefore, a treatment approach consistent with the concept of brain-gut dysfunction may focus on the neuropeptides and receptors that are present in both enteric and central nervous systems. "

http://www.med.unc.edu/medicine/fgidc/historyfunctionaldisorders.htm

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My website on IBS is www.ibshealth.com

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