What do physicians do with the foot after it is amputated?

Sent to the lab. After an amputation, the removed portion of the body is typically sent to the laboratory for examination by a pathologist and/or sent to the laboratory for cultures if indicated.
Pathology. Most hospitals have a policy that the amputated tissues be sent to pathology for evaluation. In the setting of an infection, cultures may be taken. In the setting of other disease, tissues may be evaluated by the pathologist to look at the blood vessels, for example in buerger's disease. After being evaluated amputated limbs are disposed of as "medical waste" which is typically incinerated.