Support the IBS Research Fund

Mark Pimentel, MD

Mark Pimentel, MD, leads the Gastrointestinal Motility Program and Laboratory at Cedars-Sinai.

Nearly 40 million Americans are currently experiencing the debilitating effects of irritable bowel syndrome (IBS). Research at Cedars-Sinai is bringing hope to patients seeking a cause and a cure for their IBS. With your support, we can expand our efforts and accelerate the pace of discovery. Join us by making a gift today.

Until recently, a patient diagnosed with IBS was likely to be prescribed antidepressant medication and sent to a psychologist. IBS was thought to be primarily stress–induced. At Cedars-Sinai, we understand that this disease is not "in your head," which is why we are focusing our efforts on identifying the causes.

The IBS Sequence

Our scientists have mapped out a large part of the sequence of events that lead to IBS. We now know that food poisoning, bacteria in the gut, the immune system and gut nerves can all play a role. Learn more below.

Food Poisoning

1. Food Poisoning A recent study by Cedars-Sinai revealed a link between irritable bowel syndrome (IBS) and food poisoning. The key to understanding how IBS is triggered may be within the bacteria involved—E. coli, Salmonella, Campylobacter, Shigella, and others.

Bacterial Toxin

2. Bacterial Toxin Building on that link, the research team identified cytolethal distending toxin (CDT)—a toxin common to all bacteria that cause food poisoning—as a factor in the development of IBS. When CDT is missing, IBS is much less likely to develop.


3. Autoimmunity Analysis revealed that the bacterial toxin, CDT, causes the immune system to form an antibody that attacks nerves in the small intestine. We do not yet know what causes antibodies to attack, but further research could lead to answers.

Gut Nerve Damage

4. Gut Nerve Damage With fewer nerve cells in the small intestine, the normal rhythm of the digestive tract is disrupted. Our investigations show that unbalanced motility may lead to a common condition called small intestine bacterial overgrowth (SIBO).

Bacterial Overgrowth

5. Bacterial Overgrowth The type of bacteria present in the small intestine—hydrogen-producing bacteria or methane-producing bacteria—can determine the type of IBS a patient will develop. Antibiotic treatment targeting specific bacteria have found to be effective in reducing IBS symptoms.


6. IBS Symptoms The symptoms of IBS are influenced by the combination of the nerve/function changes of the gut, the buildup of bacteria in the small bowel, and the type of bacteria present.

This is only the beginning. The need for more answers is urgent, and peer–reviewed research will be the key to unlocking the mysteries behind this disease.

Unfortunately, funding from public sources is limited. With new discoveries on the horizon we need private funding from supporters like you to continue our quest for answers.

Invest in tomorrow's breakthroughs and a brighter future for IBS patients. Make a gift to Cedars-Sinai's IBS Research Fund.