Mechanism of oxalate kidney stones in patient with malabsorption

Explanation

In the normal gut, calcium binds with oxalate in the intestines, makes it insoluble and this calcium oxalate leaves the body.

When fat gets malabsorbed, it holds on to calcium, leaving the oxalate free. The  body can absorb the unbound oxalate & the poor kidney gets overwhelmed with these amounts thus  forming  Oxalate stones.