You need to go for A Radiological examination -CT PNS and A clinical examination - Diagnostic Nasal Endoscopy. plus your Mucus needs to be cultured and depending on culture reports we can start you on sensitive antibiotics.(as you are mentioning it to be green)
Next Steps
CT PNS
Diagnostic Nasal Endoscopy
CULTURE SENSITIVITY REPORTS FROM NASAL DISCHARGE
to Start reports based sensitive antibiotics
Regular Alkaline Nasal Washes
Health Tips
The very purpose of sinus surgery is to facilitate ventilation and drainage of sinuses, So if you are concerned with excessive mucus being produced or drained pls don't worry- it's normal post sinus surgery. Pls do regular nasal washes, you will be good.
PS- Follow above advice as you are concerned with green mucus being produced, which Can Be because of infection. (*can be).