Diagnostic and therapeutic strategies in the irritable bowel syndrome.

The management of patients with irritable bowel syndrome (IBS) is a frequent, yet challenging task in both primary care and gastroenterology practice. A diagnostic strategy guided by keen clinical judgment should focus on positive symptom criteria and on the absence of alarm symptoms. In younger patients lacking alarm features, invasive testing has a low-yield. The presence of food intolerance and underlying celiac disease should be excluded. The usefulness of fecal tests such as calprotectin and lactoferrin to exclude organic bowel disease is not adequately established. In patients with moderate to severe symptoms who fail initial therapeutic trials, further tests can be performed in tertiary care settings, such as transit measurement and tests for diagnosing pelvic floor dysfunction. Treatment strategies for IBS are currently directed at the predominant symptoms. In diarrhea-predominant IBS, opioids (e.g. loperamide) and the 5-HT(3) receptor antagonist alosetron are efficacious. In constipation-predominant IBS, fiber and bulk laxatives are traditionally used, but their efficacy is variable and may worsen symptoms. The 5-HT(4) receptor agonist tegaserod is efficacious in female patients with IBS and constipation. In patients with IBS and abdominal pain, antispasmodics and antidepressants can be used, with the best evidence supporting the prescription of tricyclic antidepressants. The efficacy of psychological treatments in terms of relieving the symptoms of IBS is still uncertain. Limited evidence suggests that anti-enkephalinase agents, somatostatin analogues, alpha(2)-receptor agonists, opioid antagonists, selective serotonin reuptake inhibitors, probiotics and herbal treatments may be useful in IBS patients.