INTRODUCTION: Fast Track Colorectal Clinics are becoming a requirement to meet the government's 10-day rule for patients with suspected cancers to be seen by a specialist. However, such clinics soon tend to get overwhelmed by huge numbers of referrals, many of them inappropriate. The Association of Coloproctology of Great Britain and Ireland has published criteria for appropriate referral. We evaluated the sensitivity of these criteria and attempted to recommend appropriate changes. METHODS: Data of 50 consecutive colorectal cancers from our DGH since January 2000 has been collected in relation to demographics, presenting signs and symptoms, haemoglobin levels as well as treatment. The new Criteria were then applied strictly to these cases and we evaluated whether these patients would have been eligible for fast track referral, if these criteria had been in force since January 2000. RESULTS: Forty-one (82%) of 50 patients would have been eligible for referral as follows: 11 (22%) rectal bleeding with diarrhoea; 8(16%) persistent diarrhoea without bleeding (>60 years), 12 (24%) bleeding without anal symptoms (>60 years), 0 (0%) palpable right sided abdominal mass, 7 (14%) palpable rectal mass, 16 (32%) iron deficiency anaemia (<11 g/dl in men & <10 g/dl in women), 10 (20%) patients qualifying on more than one criterion. However, 9 (18%) patients had presenting features that would have excluded them from a fast track referral as follows: 4 (8%) only abdominal pain + weight loss (48, 54, 72, 75 years old), 2 (4%) change in bowel habit + no rectal bleeding (54, 57 years old), 1 (2%) palpable mass at a site other than the right side of the abdomen. CONCLUSIONS: We feel that this study, although small, highlights the dangers of having very rigid criteria for such clinics. The new criteria though high in specificity have low sensitivity for safety. We recommend some modifications to the criteria as follows: rectal bleeding without anal symptoms >50 years instead of 60 years; patients with a palpable mass anywhere on the abdomen; and the adddition of a new criterion of abdominal pain with weight loss. These modifications would significantly increase the sensitivity from 82% to 94%.