The exact cause of IBS remains unknown
Medical science has tended to ignore IBS; it wasn't appreciated how much of an impact it can have on a patient's quality of life," he says.
But not all fiber is the same. The soluble fiber ispaghula husk, which is also known as psyllium and found in some bulk laxatives, significantly reduced symptoms of IBS, particularly constipation; insoluble fiber, such as bran, did not relieve symptoms.
Several antispasmodic drugs helped prevent IBS symptoms, particularly diarrhea. The most effective one was hyoscine, which is sold without a prescription in the United States.
Although peppermint oil was found to be the most effective of the three therapies, more data are needed, cautions Quigley.
Dr. Wilson adds that such treatments are best for patients with mild or moderate IBS. However, in her practice, she's found that prescription medications need to be used for severe cases that don't respond to these treatments.