Primary care has a substantial role in reducing the public health burden of colorectal cancer. Given that mortality from colorectal cancer increases with more advanced disease at diagnosis1 and that most patients present with symptoms that prompted them to consult their general practitioner,2 both patients and doctors need to recognise the symptoms that suggest a high risk of cancer.

In this week's BMJ du Toit and colleagues report a 10 year prospective study which confirms the importance of rectal bleeding as an indicative symptom for colorectal cancer.3 The study found that about one in 10 patients with new onset rectal bleeding had cancer. The authors say that general practitioners should investigate anyone aged 45 years and older who presents with rectal bleeding, with or without a change in bowel habit.

Lower gastrointestinal symptoms …