Aminosalicylates and other anti-inflammatory compounds for irritable bowel syndrome.

Growing evidence suggests that gastrointestinal immune activation may affect intestinal function and sensory perception, which contribute to symptom generation in patients with irritable bowel syndrome (IBS). The identification of higher counts of immunocytes (e.g. T cells and mast cells), mucosal and systemic immune activation, and increased mucosal permeability in patients with IBS has stimulated interest in the potential development of therapeutic approaches aimed at targeting the immune system and inflammation. Although an initial attempt in a pilot trial with steroids in patients with post-infective IBS failed, there has been renewed interest for mast cell stabilizers and the therapeutic potential of aminosalicylates. A recent randomized, double-blind, placebo-controlled pilot trial assessed the effect of mesalazine on intestinal immune cells and symptom perception in patients with IBS. Mesalazine markedly reduced mucosal immune cells and mast cells in particular, compared to placebo. In addition, mesalazine significantly improved general well-being. Mesalazine may enhance epithelial barrier function, and preliminary data suggest that it may alter faecal bacterial profiles in IBS patients. Nevertheless, the exact mechanism through which this drug affects immune activation in the intestine of patients with IBS remains unknown. There is a need for further studies to prove the efficacy of mesalazine for IBS. Further studies aimed at assessing the role of aminosalicylates and other approaches with potential anti-inflammatory activity, including probiotics, non-absorbable antibiotics, histamine receptor antagonists and protease inhibitors on IBS symptoms or pathophysiology are now warranted.

Chronic intestinal pseudo-obstruction.

Chronic intestinal pseudo-obstruction (CIPO) is a severe digestive syndrome characterized by derangement of gut propulsive motility which resembles mechanical obstruction, in the absence of any obstructive process. Although uncommon in clinical practice, this syndrome represents one of the main causes of intestinal failure and is characterized by high morbidity and mortality. It may be idiopathic or secondary to a variety of diseases. Most cases are sporadic, even though familial forms with either dominant or recessive autosomal inheritance have been described. Based on histological features intestinal pseudo-obstruction can be classified into three main categories: neuropathies, mesenchymopathies, and myopathies, according on the predominant involvement of enteric neurones, interstitial cells of Cajal or smooth muscle cells, respectively. Treatment of intestinal pseudo-obstruction involves nutritional, pharmacological and surgical therapies, but it is often unsatisfactory and the long-term outcome is generally poor in the majority of cases.