A drainable ostomy appliance , comprising: side walls of flexible sheet material sealed to one another along a portion of their respective peripheries to define a collection cavity , the side walls being a body side wall and a non-body side wall, the side walls defining a downwardly extending neck portion terminating in a discharge outlet at which the side walls are not sealed to one another, the discharge outlet being closed by folding the neck portion upwardly and opened by unfolding the neck portion downwardly for draining the contents from the cavity ; an inlet in the body side wall; and a closure system comprising: a first portion of the closure system on the body side wall and a second portion of the closure system on the non-body side wall, wherein the first portion of the closure system comprises at least one body side closure member and the second portion of the closure system comprises at least one non-body side closure member , characterised by the at least one non-body side closure member including an enlarged head portion on an end thereof, and a fastening system, wherein in an open state, the neck portion is unfolded and in a closed state, the neck portion is folded upwardly at least two times and secured in the closed state using the fastening system, wherein the side walls of the neck portion are folded around the enlarged head portion of the at least one non-body side closure member at a first fold. side walls of flexible sheet material sealed to one another along a portion of their respective peripheries to define a collection cavity , the side walls being a body side wall and a non-body side wall, the side walls defining a downwardly extending neck portion terminating in a discharge outlet at which the side walls are not sealed to one another, the discharge outlet being closed by folding the neck portion upwardly and opened by unfolding the neck portion downwardly for draining the contents from the cavity ; an inlet in the body side wall; and a closure system comprising: a first portion of the closure system on the body side wall and a second portion of the closure system on the non-body side wall, wherein the first portion of the closure system comprises at least one body side closure member and the second portion of the closure system comprises at least one non-body side closure member , characterised by the at least one non-body side closure member including an enlarged head portion on an end thereof, and a fastening system, a first portion of the closure system on the body side wall and a second portion of the closure system on the non-body side wall, wherein the first portion of the closure system comprises at least one body side closure member and the second portion of the closure system comprises at least one non-body side closure member , characterised by the at least one non-body side closure member including an enlarged head portion on an end thereof, and a fastening system, wherein in an open state, the neck portion is unfolded and in a closed state, the neck portion is folded upwardly at least two times and secured in the closed state using the fastening system, wherein the side walls of the neck portion are folded around the enlarged head portion of the at least one non-body side closure member at a first fold. <EOS>