Try something like this:

if exists(SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS

 WHERE TABLE_NAME = 'RESULTS'

 AND COLUMN_NAME = 'TOTAL_VOTES')

BEGIN

        SELECT 0

END

ELSE

BEGIN

 exec('ALTER TABLE [dbo].[RESULTS] ADD [TOTAL_VOTES] int not NULL DEFAULT (0);')

 exec('UPDATE RESULTS SET TOTAL_VOTES = (OPTION1 + OPTION2 + OPTION3 + OPTION4 + OPTION5 + OPTION6 + OPTION7 + OPTION8 + OPTION9 + OPTION10);');

END