Updates in IBS News and Research

A roundup of brief summaries of news and research about irritable bowel syndrome.

Experimental Drug May Treat IBS with Fewer Adverse Side Effects

Medication aimed at treating chronic constipation and constipation predominant irritable bowel syndrome, currently in Phase 2b/3 clinical trials, does not cause diarrhea.

Report Finds Significant Unmet Therapeutic Need for IBS and other Bowel Disorders

Analyst reports that “the IBS pipeline is relatively dry as drug developers struggle to unwind the complex pathology behind this disorder. The main unmet need in IBS is effective therapies indicated specifically to alleviate the symptoms of this syndrome.”

Unproven Tests for IBS Fail to Meet Established Standards

Australian researchers recently conducted a comprehensive literature review to assess the evidence supporting the use of various IBS tests and assessments frequently promoted and used by alternative and complementary medical practitioners. Based on ACCE (Analytic validity, Clinical validity, Clinical utility and Ethical, legal and social implications) criteria for diagnostic tests, “Serum immunoglobulin G (IgG) to food antigens, salivary IgA, intestinal permeability, fecal short-chain fatty acids and fecal microbial analysis” and others failed to satisfy the ACCE criteria and “were deficient in one or more areas of analytical validity, clinical application, validity and ethical usage standards.” The authors of the study wrote that such “alternative investigations lack reliability and direct clinical applications, and should not be recommended for the investigation of gastrointestinal symptoms.”

The Role of Neuroendocrine Markers and Psychological Factors in IBS

Researchers evaluated 125 consecutive IBS patients and 105 healthy subjects, recording plasma serotonin, plasma and urinary cortisol, and plasma neuropeptide Y levels and assessing patients for IBS symptom severity. Sixty-six patients received a psychodiagnostic evaluation, as well. The researchers reported a high incidence of specific psychological features in IBS patients, including state anxiety, trait anxiety, and obsessions and compulsions. They also reported a positive correlation between neuropeptide Y and state anxiety and simulation/social ingenuity. In diarrhea-predominant IBS, plasma cortisol was linearly related to plasma serotonin.

Is it Microscopic Colitis or IBS?

Researchers from the Mayo Clinic, Rochester, and the University of California, San Diego, evaluated a cohort of 120 patients with biopsy-proven microscopic colitis to determine which patients also met diagnostic criteria for IBS. They found that 38-58% met the diagnostic criteria for IBS, concluding that “these criteria are not specific enough to exclude the presence of microscopic colitis.” They recommend that colonoscopy with mucosal biopsies should be performed in patients with watery diarrhea if symptoms are not controlled by antidiarrheal medications.