ERCP is performed using a conventional duodenoscope as described in the literature. To exclude contamination artefacts, smears of the endoscope working channel (elevator) will be taken before and after the examination. Furthermore buccal smears and stool samples will be taken to get an impression of the individual transient flora. Endoscopic transpapillary bile duct biopsy for diagnosing an invasive fungal infection will be performed. Transpapillary biopsies as confirmed by the present literature cause no increased risk for post-interventional bleeding and infection [9-12]. Additionally with routinely taken blood samples (hemoglobin and lipase), candida-antigen-serology and blood-cultures will be gained.