drupal_uninstall_schema

drupal_uninstall_schema($module)

function drupal_uninstall_schema($module) {
  $schema = drupal_get_module_schema($module);
  _drupal_schema_initialize($schema, $module, FALSE);

  foreach ($schema as $table) {
    if (db_table_exists($table['name'])) {
      db_drop_table($table['name']);
    }
  }
}