The probiotic E. coli strain Nissle 1917 for the treatment of collagenous colitis: first results of an open-label trial.

Background: Collagenous colitis is clinically characterized by watery diarrhoea and can histologically be diagnosed by a thickening of the subepithelial collagen layer and an inflammatory infiltrate in the lamina propria. So far, the pathogenesis of collagenous colitis and the role of luminal factors remain unclear.

Methods: This clinical pilot investigation was conducted with an open-label design to monitor the clinical effects of EcN on stool frequency and stool consistency in 14 patients (11 female, 3male; age: 58.