Hello... This is Dr. Pavan. Glad to answer ur query. The Corns on the undersurface of feet are caused due to some abnormality in walking or in the footwear. There is high chances that if the Corns are not treated in its earlier stages, it might get deeper and cause more problem and pain while walking. Medical treatments helps to remove the corns only in its initial stages. Once deep, then the surgical excision gives maximum relief. It will be just a small surgery.