An apparatus includes a flexible catheter which may have a plurality of lumens extending from a proximal end to a distal end, a suction opening in fluid communication with a first lumen, a plurality of irrigating openings in fluid communication with a second lumen, a dilator in fluid communication with a third lumen and an occluding balloon in fluid communication with the fourth lumen. The catheter may be used to dilate an ostium, occlude the ostium, irrigate a sinus, and suction a sinus.