A device for lavage of a paranasal sinus having an ostium, said device comprising: a catheter (1800,1900) having a proximal end, a distal end, an infusion lumen (1812,1902), an aspiration lumen (1810,1914), an infusion outlet aperture (1806,1904) and an aspiration inlet aperture (1808); and a balloon (1804,1912) for occluding a paranasal sinus ostium located on the catheter proximal to the infusion fluid outlet aperture and aspiration inlet aperture, whereby lavage fluid may be infused through the infusion lumen, out of the infusion outlet aperture and into the paranasal sinus and such lavage fluid may then be aspirated from the paranasal sinus through the aspiration inlet aperture and through the aspiration lumen.