• The root cause of colon cancer is clumps of non-cancerous cells, called polyps, that eventually turn malignant and spread to other organs. Colon cancer often manifests few symptoms and is notoriously difficult to detect; though the disease is highly curable in its early stages, most patients have progressed to advanced stages of colon cancer before they begin experiencing any signs of the disease.
  
  

Bowel Movement Problems

• People with stage IV colon cancer often experience abnormal bowel movements, whether in the form of constipation or diarrhea. Another common symptom is the feeling that not all the waste has been emptied after a bowel movement. Pain near the rectum is also possible, but not common.
  
  

Changes in Stool

• Changes in the consistency or color of the stool is not uncommon, as is blood in the feces or bleeding of the rectum. Signs of stage IV colon cancer include stool that is covered with mucus, unusually dark or black, or stool that is narrower than usual for the patient.
  
  

Weakness

• Colon cancer tumors can cause chronic internal bleeding, which decreases red blood counts and makes the patient anemic, resulting in fatigue, weakness, pale skin and heart palpitations.
  
  

Weight Loss

• When polyps grow and spread throughout the colon, they can decrease the sufferer's appetite and cause unintentional weight loss.
  
  

Abdominal Pain or Nausea

• Severe lower abdominal pain that continues for several weeks is a characteristic sign of advanced colon cancer. The pain may be from gas, or it may be unexplained. The abdomen may be visibly swollen, and there may be one or more lumps found by touch.
  
  

Jaundice

• Stage IV colon cancer often spreads to the liver, which can cause jaundice (the yellowing of the skin) and abdominal pain, as liver function is compromised. Unusually pale stools are another sign that the colon cancer has spread to the liver.
  
  

Unexplained Fever

• A fever with no apparent bacterial or viral infection is a potential symptom of colon cancer, as the immune system attempts to kill the disease. Along with fever often come other symptoms of having cancer in the body, usually thrombosis, or blood clots.