Stool Guaiac test for occult blood
Urinalysis
Leukocyte count
Anemia
Elevated serum level of carcioembryoinic antigen (CEA)
Barium enema (fixed filling defect with an annular configuration (apple core), an intraluminal mass, or constriction
Abdominal ultrasound
Abdominal C.T. scan for detection of distant metastases
M.R.I. for detection of distant metastases
Proctosigmoidoscopy or colonoscopy