What are the key symptoms and signs that should prompt a referral for suspected rectal cancer?

Key symptoms and signs that should prompt a referral for suspected rectal cancer include:

• Unexplained rectal bleeding in people aged 50 and over, for which quantitative faecal immunochemical testing (FIT) should be offered initially.
• Rectal bleeding accompanied by unexplained abdominal pain or weight loss in adults under 50, also warranting quantitative FIT.
• Detection of a rectal mass on digital rectal examination, which should prompt a suspected cancer pathway referral.
• Unexplained anal mass or anal ulceration, which should also lead to consideration of a suspected cancer pathway referral.

These features are considered red flags for colorectal cancer and require urgent investigation or referral according to NICE NG12 guidelines.