Although there is much we do not know about the physiological causes of IBS symptoms, the Neuroenteric Disease Program, and other research groups, have identified an over-sensitivity of the gastrointestinal tract as one contributing factor. The colon and rectum of patients with IBS seem to respond differently to natural processes such as pressure and stretch which follow meals or normal contractions. This increased sensitivity begins in the nerves which sense what is taking place in the colon and rectum, and may result in an over-reaction in the brain and in turn the nerves which send messages back to the GI tract. This can set up a vicious cycle of symptoms (including pain) and the feeling “something is wrong” even though only normal digestion is taking place. Understanding IBS hypersensitivity can lead directly to new medications which may control this process, and get at the root cause of IBS symptoms.

Despite some important new findings which have greatly increased our understanding of the hypersensitivity factor in IBS (some of which has been reported in previous newsletters), there have been no studies which have examined how hypersensitivity and symptoms may go together over time. This is a very important question since IBS is not a stable problem, and it is important in developing new treatments to know what makes symptoms get better or worse. The Neuroenteric Disease Program is beginning a new study to look at this question. We will be following a group of volunteers with IBS and a small group of non-IBS subjects over a one-year period. Volunteers will be studied once every three months to evaluate their current symptoms and GI tract sensitivity. The sensitivity testing will be done using our standard testing procedures using a small balloon placed in the rectum. On two occasions, at the beginning and end of the one year study, we will also examine the parts of the brain which are active during GI tract stimulation using Positron Emission Tomography (PET) scans. The PET scan evaluates how much different parts of the brain are working and has in a previous study shown significant differences between volunteers with and without IBS. Volunteers will be financially compensated for participation and will also receive a color photograph of their brain from the PET testing sessions. We are very excited about this new project since it will be the first study ever done which has looked at the physiological changes which might determine symptom patterns in IBS patients over time.

If you might be interested in participating in this ground-breaking study, please call (310) 268-3432.