Corns are a frequent problem on the foot. They are a natural reaction to pressure as the skin thickens up to protect itself from that pressure. At some stage this process breaks down and gets so thick that it's painful. There's a persistent myth that corns have roots that they keep growing back from whenever you try to remove them. This is like the analogy of plants that grow back from their roots if you chop the top of the plants off. That analogy has been applied to corns because they keep growing back, however they do not possess roots to grow back from.
Corns originate from pressure and a competent podiatric doctor can readily remove a corn. However, after the corn is taken away if the pressure which caused it is still there then, of course, it is going to grow back. It grows back simply because the cause continues rather than because the podiatrist left a root there for this to grow back from. That pressure may be from a poor fitting shoe or from something like a mallet toe or hallux valgus which leads to increased pressure on an area. When the corn is beneath the foot, then the cause is greater pressure on the location where the corn is, most likely because of the way you walk.
The misconception continues given that they do return, so its essential to get rid of the cause at the same time the corn is removed. There is absolutely no root to be taken out. This means that the pressure on the foot the location where the corn has been has to be decreased or removed. This may involve issues like using better fitting footwear or the use of padding to get pressure off the area where the corn is. Occasionally surgery will be necessary to the bone underneath the corn to get rid of the pressure. If that cause isn't taken away or decreased then the corn will return, so it is easy to see where the myth regarding corn roots originates from.