Have had root canal re treatment and now 3 years later i see puss ball on gum when squeezed blood comes out , comes and goes ?

Parulis fistula: is a sign that there is chronic infection and your body is draining it out. Unlike some other types of infection, a chronic dental abscess will not get better on its own. See an endodontist for definitive diagnosis and treatment options. Good luck.

Abscess: The tooth needs to be re-evaluated. Please call your treating dentist for an appointment.