These are often
highlighted as important in the detection of patients with bowel cancer because almost a
third have an associated iron deficiency anaemia (IDA). When this is severe it can cause lethargy, fatigue and tiredness. However only a small number of
bowel cancer patients present with IDA low enough to produce symptoms and in these patients the IDA is usually detected as the result of a routine blood test in patients with one of
the three key symptoms rather than because of the symptoms of
anaemia.
Note
The high prevalence of IDA in patients with bowel cancer means that testing for anaemia in patients presenting with one of the
three key symptoms is a very good way for GPs to
determine whether these patients require further investigations in hospital.