Irritable Bowel Syndrome Message Boards

Are you a Gut Responder?
Hints on Coping with IBS

http://www.aboutibs.org/Publications/gutResponder.html

"Increased stress mediators in IBS.There is increasingevidence to support the prominent role of stress in the
pathophysiology and in the clinical presentation of IBS
symptoms. There are few published reports on alterations
in stress mediators, such as catecholamines and cortisol to
stress or visceral stimulation in IBS. Several studies have
reported increased in catecholamines (norepinephrine and
epinephrine) and cortisol levels in IBS patients. However,
it remains to be determined whether these neuroendocrine
alterations play a direct role in gut function and symptom
generation. "

"Altered brain-gut communication in IBS.A unifyinghypothesis to explain the functional bowel disorders is that
they result from a dysregulation of the brain-gut axis. An
evolving theory is that normal gastrointestinal function
results from an integration of intestinal motor, sensory,
autonomic and CNS activity and GI symptoms may relate
to dysregulation of these systems. Brain imaging studies
such as functional magnetic resonance imaging (fMRI) and
positron emission tomography (PET) have been performed
in IBS patients to measure brain activation patterns to
visceral stimuli. These studies suggest that brain
activation responses to visceral stimuli are distinctly
different in IBS patients compared to healthy individuals.
IBS patients may have different emotional and cognitive
processing of sensory information from the gut compared
to healthy individuals. "

They have observed an increase of mast cells in IBS, they can be actived by stress without a pathogen and in turn release toxins onto the smooth muslce nevers and hence cause pain and symptoms.

There are also problems with the brain in IBS and the singals it receieves from the gut. The prefrontal cortex is "turned up" and that is in part an anxiety center.

"What would be an example of new understanding?
Well one example is that we're starting to understand how the brain is responding to the pain in IBS. There have been some studies done where they've artificially created a kind of an irritable bowel by placing a balloon to stretch the bowel, and that produces pain. Then they've compared people with IBS to non-IBS, or "normal" individuals. And what they've found is that when you stretch the bowel-and use PET scans to monitor the response-in normal individuals, certain areas of the brain that register pain respond and release chemicals called neurotransmitters that suppress and lower the pain. But it seems that doesn't happen as well in people with IBS. In fact, in people with IBS another area of the brain responds that is associated with anxiety. So what we find is that people with IBS, aside from having a bowel problem, may have some difficulty in terms of the way their brain is regulating the pain."

Serotonin is very important here for gut function and anxiety, almost all IBS patients seen by gastro docs, effectively demonstrate serotonin dysregulation.

"Neuroimaging has provided evidence of physiological differences between normal individuals
and those suffering from IBS in the way a visceral stimulus (ie, rectal distention) is processed in
the brain.[14,15] Initial data from positron emission tomography (PET) scans demonstrated
increased activation of the anterior cingulate cortex (ACC) among normal individuals, compared
to IBS patients. The ACC is a cerebral cortical area that is rich in opiate receptors and is thought
to be a major component of cognitive circuits relating to perception as well as descending spinal
pathways involving pain. More recently, fMRI was used to demonstrate increased activity in the
ACC, prefrontal (PF), and insular cortex areas, and in the thalamus of IBS patients compared to
normal individuals."

There is a ton of information on all this and how it all works.

The Neurobiology of Stress and Emotions
By: Emeran A. Mayer, M.D., UCLA Mind Body Collaborative Research Center, UCLA School of Medicine, California

"What does this have to do with IBS
Converging evidence from different laboratories and research groups are consistent with the concept of an "enhanced stress responsiveness" as a major vulnerability factor in many IBS patients. As outlined above, such an enhanced stress responsiveness may not be obvious to the affected individual, until he or she is exposed to a period of sustained threatening stressors (financial or employment problems, divorce, aftermath of a major disaster with consequences on daily life), repeated mild to moderate stressors, or a one time severe (life threatening) type stressor (robbery or physical assault). Under these circumstances the mechanisms that normally turn off the stress response are overwhelmed, and attempts of the nervous system at adaptation or habituation fail. Many of the vulnerability factors for such enhanced stress responsiveness have been identified and many of them occur in a particular vulnerable period of the developing brain (before age 10). Some of the best-studied factors include loss of the primary care giver, distant mother-child relationship, emotional neglect, and physical and verbal or sexual abuse.

In order to understand how a chronically enhanced stress response can produce the cardinal symptoms of IBS (abdominal pain and discomfort associated with altered bowel habits) we have to go back to the earlier section on the emotional motor system: activation of the stress system will stimulate contractions and secretion in the sigmoid colon and rectum. Depending on the specific emotional context (fear vs. anger), the upper GI tract will be either inhibited (fear) or stimulated (anger). In addition, recent research in animals has demonstrated a phenomenon referred to as stress-induced visceral hyperalgesia. What this means is that in vulnerable animals, exposure to an acute moderate stressor will make the colon more sensitive to distension (and the perception of discomfort or pain).

"Perceptions of pain, muscle tensions, and other somatic symptoms can cause stress levels to spiral upward. Self-regulation strategies that reduce unpleasant symptoms offer both physical and psychological relief."
�R. Sovik
Why do the symptoms go away after one stressful situation has resolved and persist in another? Amongst many factors, anxiety and fear generated by IBSsymptoms themselves are sufficient in many patients to maintain the stress responsiveness in a chronically enhanced state. Some of the more common symptom related anxieties include: Am I close enough to a bathroom when my symptoms come on? Will I be OK for the rest of the day, unless I completely empty my colon in the morning before leaving the house? "

http://www.aboutibs.org/Publications/stress.html

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My website on IBS is www.ibshealth.com

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