The clinical features of colonic carcinoma depend on the precise site involved. They are best considered in terms of those features produced by the tumour itself, those produced by the presence of local secondaries, and those produced by other effects of the tumour.
Local effects of the tumours:
- change in bowel habit - diarrhoea or constipation, or the two alternating with each other. The diarrhoea may contain profuse amounts of mucus. This may be due to excessive secretion by the tumour. The tumour may be bleed and rectal bleeding or a positive faecal occult blood test may result. Rarely melaena may occur.
- intestinal obstruction - pain, distension, absolute constipation - and vomiting. This may be acute, i.e. sudden and severe, chronic, i.e. insiduous and slowly progressive, or acute on chronic, i.e. chronic that becomes acute as obstruction becomes complete.
- perforation - into the general peritoneal cavity or locally, by a pericolic abscess, or by fistulae into adjacent viscera, e.g. gastro-colic, vesico-colic fistulae.
The effects of secondary deposits:
- jaundice
- abdominal distension due to ascites
- hepatomegaly
The general effects of malignant disease:
- anaemia
- malaise
- anorexia
- loss of weight