What causes my toe to be painful after 5months later after toenail surgery phenol was applied to the site callus has been removed but still sore why?

Irritation/Bone: There are some reasons why people still have pain after the nail surgery. If there is a callus in the area, this would imply mechanical irritation. Some things to consider are shoe styles and size. An x-ray might reveal what the eye cannot see.

Sore Toe: Prolong tenderness is a less common occurrence but still a possibility with nail removal. So long as there is no extending redness or drainage there may have been a nerve that is now sensitized after the procedure. I would return to whoever performed the procedure and ask more questions. Or see a podiatrist.

Causes for pain are:: 1: possibly all nail/its root may not have been removed; 2: recurrence from its root (matrix); 3: possible injury to the toe during healing period can delay the healing; 4: maybe a low grade infection is causing persistence of the pain. See your surgeon and if no improvement then get a second opinion. But phenol can result in local injury to the tissues which needs more time to heal completely.