ABSTRACT
Mast cells are believed to play a role in irritable bowel syndrome pathogenesis and symptom genesis due to their close neighborhood to gastrointestinal innervations. This study was designed to evaluate the efficacy of orally administered cromolyn for reduction of symptoms in patients with irritable bowel syndrome [IBS]. A randomized placebo-controlled double-blinded 6x6 weeks cross-over study was performed in a private gastrointestinal clinic. 10 patients were allocated to group A and 6 patients to group B. Patients in group A received 150 mg cromolyn divided in three equal doses for the first 6 weeks and placebo for the next 6 weeks but patients in group B received placebo for the first 6 weeks and cromolyn in the next 6 weeks. Weekly evaluation was performed and visual analogue scale was used to determine severity of symptoms. Sixteen patients completed the study. Mean age of the patients was 40.3 +/- 10.9 years old [range: 24-57]. Eight patients had D-IBS [Diarrhea dominant] and other 8 had CIBS [Constipation dominant]. Both cromolyn sodium and the placebo decreased the severity of bloating [Freidman test, p 0.001 and 0.006 respectively]. The severity of the main symptom [diarrhea or constipation] did not decrease in patients of group A and B who were treated with different sequences of the drug or placebo. The severity of pain decreased drastically after 6th week of treatment with cromolyn. Freidman test showed a significant difference between the pain levels of the former defined treatment spots [p 0.01, and 0.02 for patients in group A and B, respectively]. No adverse drug reactions were observed during the study. In conclusion, long term administration of cromolyn seems to be partially effective for treatment of abdominal pain in patients with IBS while main symptoms [diarrhea or constipation] might not decrease during this treatment