A device for sealing a fistula includes a first flange for orienting against a first wall of the fistula, a second flange for orienting against a second wall of the fistula, and at least one stem coupling the first and second flanges. Illustratively, the at least one stem is elastomeric. The stem(s) exhibit(s) an elongation of greater than about 0.6 mm/N of force applied between the first and second flanges in the range of elongation of about 0 mm to about 15 mm. Additionally or alternatively illustratively, the stem(s) comprise(s) (an) elastomeric tube(s) including (a) wall section(s) having a varying radius along its (their) length(s). Additionally or alternatively illustratively, the stem(s) pass(es) through (respective) opening(s) provided in at least one of the first and second flanges to permit adjustment of the location of at least one of the first and second flanges along the length of the stem(s).