The chronic suppurative otitis media is of two types:
Majority of cases fall in this type of infection. This infection is usually in the anterio inferior segment of the middle ear cleft. It is not the dangerous type of infection.
This type of infection is less common and involves the posterio superior segment of the middle ear cleft. In this type of C.S.O.M., the changes in the mucous membrane are proliferative granulation tissue, polypus and cholesteatoma formation.
Mixed i.e. gram +ve cocci mixed with gram -ve bacilli. Also present are a wide range of both the aerobic and anaerobic microbes.