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.