Overview

Colorectal cancer develops in the colon or rectum. It usually begins as small growths called polyps on the inner lining of the intestine. Over time, some polyps may become cancerous. The condition often develops gradually over several years. Early stages may not cause symptoms. As the tumor grows, changes in bowel habits may occur. Risk increases with age and family history. Screening is highly effective in early detection. When diagnosed early, colorectal cancer is often treatable. Advanced disease may spread to liver or lungs. Regular medical evaluation is important for prevention.

What Happens During Allergic Rhinitis?

Abnormal cells grow within the lining of the colon or rectum. These cells form a tumor that may invade deeper layers of the intestinal wall. The tumor may obstruct the bowel. Cancer cells can spread through blood or lymph vessels to distant organs.

Diagnosis

Diagnosis involves colonoscopy to visualize and biopsy suspicious lesions. Stool tests may detect hidden blood. Imaging studies such as CT scan assess spread. Biopsy confirms malignancy and tumor characteristics.