White stuff coming out of the tonsils is typically pus or tonsil stones. The white stuff is often indicative of an infection, according to WebMD.
If the white stuff is accompanied by white or red spots, a sore throat and a fever, it is likely that the person is suffering from strep throat, as stated by the Mayo Clinic.
If the white stuff is more solid and accompanied by swollen tonsils, ear pain and throat pain, tonsillitis may be the cause.
Both strep throat and tonsil stones typically require a course of antibiotics. Only a doctor can properly diagnose the white stuff on the tonsils.