Specific investigations for left-sided cancer

Specific investigations for left-sided colonic carcinoma include:

• abdominal x-ray: proximal colon and caecum may be distended if there is obstruction
• barium enema: the carcinoma appears as a fixed filling defect, usually 2-6 cm long, with an annular "apple core" configuration
• sigmoidoscopy: may be able to see a low growth and/or obtain a biopsy. If no growth visible, may be able to see blood and mucous high up in the bowel with semi-liquid faeces, indicating a lesion higher up
• colonoscopy: to confirm barium enema or obtain a biopsy from a lesion high up in the colon. Uncomfortable and time-consuming, so avoid for routine diagnosis.