investigations
Last reviewed 01/2018
The preferred investigations for rectal carcinoma are:
- full blood count
- blood film: test for iron-deficiency anaemia
- rectal examination: palpable mass in less than 50% of cases
- rigid sigmoidoscopy and proctoscopy: performed at the initial consultation - reveals tumours in sigmoid region and enables positive evidence by biopsy to be obtained
- flexible sigmoidoscopy
- stool sample: test for occult blood
- colonoscopy: enables inspection and biopsy of the higher reaches of the colon. Gives high sensitivity if used by an experienced operator. Requires a full bowel preparation.
- barium enema: usually reveals the tumour as a stricture or filling defect. But negative results are not uncommon, so if this occurs when the condition is suspected, repeat the investigations after a few weeks.
- IVU: a useful preoperative investigation if there is a risk of ureteric involvement.
A barium enema and other invasive tests can be particularly distressing and should not be undertaken lightly.
staging of colorectal carcinoma using Duke system
grading of colorectal carcinoma