What are the symptoms of colon cancer ?

On the onset of the disease, colorectal cancer may not cause any abnormal symptoms.

Most patients do not have specific symptoms. Tumors in the left colon and sigmoid colon cause symptoms earlier than tumors in the right colon and transverse colon. Symptoms often appear as the tumor grows into nearby tissues and organs.

The symptoms that may appear include :

• Diarrhea
• Constipation
• Stools that appear narrower than usual
• Feeling that the rectum is not completely empty after a bowel movement
• Bright red or very dark blood in the stool or rectal bleeding
• Gas, abdominal cramps, and bloating
• Fatigue or weakness
• Anemia (a decrease in the number of red blood cells) which can cause fatigue or shortness of breath)
• Nausea and vomiting
• Loss of appetite
• Weight loss
• Respiratory problems
• And many other symptoms: pain or discomfort in the rectum, a mass in the abdomen or rectum, bowel obstruction (intestinal blockage), swollen lymph nodes, swollen liver, jaundice, fluid accumulation in the abdomen, pain in the abdomen, back, buttocks, or legs (Source: cancer.ca Canadian Cancer Society)