Predisposing causes

• Polyps
• Heridatory cancer syndromes
• Chronic inflammation, in particular chronic ulcerative colitis (more than 10 years of pan-colitis).
• Previous gastrectomy, vagotomy (about 2 fold increase)
• Previous uretero-sigmoidostomy, (favoured operation now is ileal conduit)
• Previous cholecystectomy, controversial (probably not)

Lack of roughage in the diet is thought to be a predisposing cause, this observation was originally made by Burkitt. Epidemiological studies in the western world have shown a lower rate of colo-rectal cancer in those people that eat broccili.