Food and stuff
The tonsils have crypts (caves) in them. When you swallow, food is pushed back and then to the sides of your throat.
This causes food to be pushed into those crypts where it is trapped, mixes with bacteria
and can cause bad breath
.There is no way to prevent this other than removal of your tonsils.One can use a water pick or other safe manner to remove them.Other times it is from pus