Question: what are the signs and symptoms of stage 4 colon cancer?
Answer: Blood (usually dark red or black) in the stool.
Constipation and diarrhea. These can also be symptoms of other, less serious conditions. ... 
Long, thin, pencil-like stools. ... 
Fatigue and weakness. ... 
Abdominal pain or bloating. ... 
Unexplained weight loss. ... 
Nausea and vomiting, which may happen if the tumor causes an obstruction.