Abstract: The invention relates to a balloon catheter for treating enteroatmospheric fistulae in an open abdomen, consisting of an insertion tube that has a distal balloon arranged around the shaft and a proximal balloon arranged beneath this for sealing off the fistula, at least one injection line for filling said distal and proximal balloons with a filling medium, as well as a passage tube which is arranged transversely to said insertion tube at its base end and the lumen of which is connected to the lumen of the insertion tube and may be inserted into the intestinal tract.