After colon cancer reaches an advanced stage, symptoms such as constipation and diarrhea are atypical and are dominated by the manifestations of complications, which can lead to a diversity of symptoms.
Colon cancer affects the normal absorption and peristaltic function of the intestine and can have symptoms such as bloating, diarrhea, mucus stools, and difficulty in defecation. Secondary to malnutrition, there can be anemia, weakness, and wasting. When there is hypoproteinemia, there is dystrophic edema.
Tumors that metastasize intraperitoneally and affect the peritoneum can produce large amounts of ascites, inducing abdominal pain, and can also present with persistent abdominal pain due to peritonitis.
The tumor surface is richly vascularized and is prone to rupture of the tumor, which can result in gastrointestinal hemorrhage. The tumor may block the intestinal cavity or the intestinal stiffness may induce gastrointestinal obstruction, and then the corresponding obstructive symptoms such as abdominal pain, abdominal distension, vomiting and loss of anal defecation and exhaustion may occur.
Colon cancer is also prone to liver metastasis, with symptoms such as elevated transaminases, anorexia, loss of appetite, and jaundice.