colorectal

Colorectal refers to the colon and rectum, the final sections of the large intestine. The colon absorbs water and electrolytes and forms stool, while the rectum stores stool before elimination. Diseases of the colorectal region include colorectal cancer, colorectal polyps, and inflammatory bowel diseases such as ulcerative colitis and Crohn's disease that involve the colon or rectum.

Colorectal cancer is a malignant tumor arising from the lining of the colon or rectum. Colorectal polyps are abnormal tissue growths on the mucosa that may be benign but can progress to cancer over time. Inflammatory bowel diseases affecting the colon and rectum include ulcerative colitis and Crohn's disease.

Symptoms commonly include blood in stool, changes in bowel habits, abdominal pain, unintended weight loss, and fatigue. Some conditions may be asymptomatic in early stages.

Screening and early detection are central; adults at average risk are commonly advised to begin screening in midlife using colonoscopy, flexible sigmoidoscopy, CT colonography, or stool tests such as FOBT or FIT. Diagnosis is typically by colonoscopy with tissue biopsy and imaging for staging.

Treatment varies by condition. Colorectal cancer is usually treated with surgery to remove the tumor and regional lymph nodes, with chemotherapy and sometimes radiation therapy. Polyps are removed during colonoscopy. Ulcerative colitis and Crohn's disease are managed with anti-inflammatory drugs, immunosuppressants, and biologic therapies; surgery may be needed for severe disease.

Risk factors include aging, family history, personal history of polyps or inflammatory bowel disease, smoking, obesity, and a diet high in red or processed meat and low in fiber. Regular screening reduces mortality from colorectal cancer. The term colorectal is often used to denote both the colon and rectum together.