Patients' perceptions on the impact of coffee consumption in inflammatory bowel disease: friend or foe? -- a patient survey. - Barthel, Christiane; Wiegand, Sandra; Scharl, Sylvie; Scharl, Michael; Frei, Pascal; Vavricka, Stephan R.; Fried, Michael; Sulz, Michael Christian; Wiegand, Nico; Rogler, Gerhard; Biedermann, Luc (Nutrition Journal, 2015)