POSITIVE FOBT
All patients with positive FOBT or persistent per rectal bleeding should have a colonoscopy. This does not mean that all patients with positive FOBT have bowel cancer. Approximately 4-6% of patients with positive FOBT may have bowel cancer. A colonoscopy for positive FOBT improves early detection of bowel cancer and may reduce the risk of developing bowel cancer by detecting and removing polyps.
PER RECTAL BLEEDING
The overall risk of bowel cancer in patients with per rectal bleeding is approximately 2%*. However, the risk is increased if patients have red flag signs. Patients with red flag signs have significantly higher risk*. Red flag signs include:
•Abdominal pain
•Haematemesis
•Unexplained weight loss
•Change in bowel habit for > 3 weeks
•Abdominal pain associated with shortness of breath
•Fever
•Persistent unexplained vomiting
The most common cause of per rectal bleeding is haemorrhoids. Other causes include bleeding from diverticular disease, colitis, inflammatory bowel disease, anal fissures and polyps and bowel cancer.
