I had a right hemicollectomy two yrs ago and aim havin a ct scan sonn is there a blood test that i should be having that would detect any more cancer ?

You need follow up: Prognosis for localized colon cancer after colectomy is excellent , but need close follow up , regular examinations , need repeat colonoscopy, and scans as you mentioned. Several tumor markers available by blood test , non specific but one very frequently used is CEA levels for tumor recurrence , please follow you doctors advise with follow up visits.