Inclusion Criteria:  Those who have had symptoms of chronic rhinosinusitis (nasal discharge, postnasal drip, nasal obstruction, facial pain and pressure, lack of sense of smell) that has been previously persistent for greater than 3 months AND ≥ 18 years to ≤ 90 years AND English speaking AND Able to give written informed consent AND Local residents who will be returning to this center for postoperative follow-up care AND Indicated to undergo endoscopic sinus surgery and willing to return at 2-4, 6-8 & 12 (± 2) weeks post-op.  Exclusion Criteria:  allergy to shellfish pregnant or breastfeeding Hepatitis or blood disorders any drug allergy allergy to potato starch (due to Nexfoam)