I had nasal septum and revision surgery and there was a white thing in the middle of the nasal mucosa.

Is it literally the columella mucosa? I saw threads and something like white pewter on the nasal mucosa, so I gently scraped it with a cotton swab and it felt uncomfortable. I went to the hospital because of the threads, but they were stiff and thick white threads.
 What the heck is this? That surgeon is closed today, so I went to
 another doctor. I went to see the doctor who did the surgery next week, and he cut the thread that came out, told me not to blow my nose, gave me medicine, told me to put something like eye ointment in my nose, and gave me antibiotics.
 What is this? What kind of situation is this?