Clinical features

The clinical features of rectal carcinoma include:

• rectal bleeding:
  • haematochezia - passage of bright red blood with bowel movements
  • the bleeding is commonly persistent but rarely copious
  • may be streaked on stool or mixed with mucous
• change in bowel habit; low tumours cause slight constipation but high tumours cause alternating constipation and diarrhoea
• tenesmus
• generalised debility and malaise

Less common features include:

• pain:
  • colic, with distension and vomiting, due to lumen obstruction, or
  • pain localised to rectum, due to direct spread to surrounding structures, especially the sacral nerves,
  • rarely, pain during defaecation
• ascites
• abdominal distension
• hepatomegaly

In 90% of cases, rectal examination reveals the carcinoma:

• papilliferous tumours feel soft, frond like, and have a narrow pedicle
• villous carcinomata are often impalpable
• carcinomatous ulcers feel hard and bulge into the lumen of the rectum. Their base is irregular and friable, and they usually have an everted edge.

Reference:

1. Eng C, Yoshino T, Ruíz-García E, et al. Colorectal cancer. Lancet. 2024 Jul 20;404(10449):294-310.