Impaction n. : The driving of one fragment of bone into another so that the fragments are not movable upon each other; as, impaction of the skull or of the hip.

Impaction n. : An immovable packing; (Med.), a lodgment of something in a strait or passage of the body; as, impaction of the fetal head in the strait of the pelvis; impaction of food or feces in the intestines of man or beast.

Example:
What are signs of Impaction in chinchillas?

Taxonomy
Impaction, Dental Impaction, Treatment, Reptiles, free encyclopedia, Fecal impaction, symptoms, Humans, mass, medications, the substance, search, free dictionary, blockage, Horses, relation to, Digestion, Informal Definition.

Defination from the web:
impaction are rocks and sand which might be accidentally consumed when the reptile attacks its prey. ... Common treatments involve placing the animal in a lukewarm bath and gently rubbing the area under the impaction to help the passing of the consumed substance. ...