Symptoms of colon cancer depend upon a tumor’s localization.
Tumors localized on the right side of the colon (colon ascendens) usually manifest symptoms after the disease has already spread throughout the body and include: weight loss, and general bad health. Tumors localized in the left side of the colon (colon descendens) manifest symptoms earlier because of the bowel obstruction they cause (ileus). Tumors in the left colon are usually accompanied with abdominal pain and constipation.
Other diseases are also responsible for the same symptoms; therefore, clinical manifestations or presence of these symptoms are not enough for establishing a correct diagnosis. Colon cancer causes bleeding, even in very small amounts (occult bleeding). A fecal occult blood test is the first step in the diagnostic protocol. Then, an endoscopic colonoscopy is the next procedure that follows to identify possible problems in the bowels. You can consult a gastroenterologist to follow up.