In this example, I searched for any SP containing the text LoadByIP:
SELECT Distinct SO.Name
FROM sysobjects SO (NOLOCK)
INNER JOIN syscomments SC (NOLOCK) on SO.Id = SC.ID
AND SO.Type = 'P'
AND SC.Text LIKE '%LoadByIP%'
ORDER BY SO.Name
Update: this was suggested by nts (see comments):
SELECT routine_name, routine_definition
FROM information_schema.routines
WHERE routine_definition LIKE '%LoadByIP%'
AND routine_type = 'PROCEDURE'
Both work well :-)