Colorectal cancer may cause several symptoms . You could have polyps or colorectal cancer and not know it. Abdominal pain, aches, or cramps may be symptoms of colorectal cancer . Colorectal polyps (abnormal growths in the colon or rectum that can turn into cancer if not removed) and colorectal cancer don't always cause symptoms, especially at first. Symptoms of colon cancer can include: A change in bowel habits, such as more-frequent, looser stools or diarrhea, constipation, or changes in stool shape. Rectal bleeding or blood in the stool. Dark, black-colored tarry stools. But colon cancer can cause a more persistent, often vague form of abdominal discomfort. This may include cramping, gas pains, bloating, or a sensation of fullness that doesn’t go away after a bowel movement. As the tumor enlarges, it may partially block the intestine, causing food and waste to move less freely. WHO fact sheet on colorectal cancer , including risk factors, symptoms , treatments and prevention.
