Bowel cancer develops in the colon or rectum and produces several warning signs that warrant medical attention. Common symptoms include persistent changes in bowel habits, blood in stool, abdominal pain, unexplained weight loss, and fatigue. These signs can indicate other conditions, but doctors recommend evaluation if they persist for more than two weeks.
Risk factors include age (most cases occur in people over 50), family history of bowel cancer, inflammatory bowel disease, obesity, smoking, heavy alcohol consumption, and a diet high in red or processed meat. Physical inactivity also increases risk.
Screening programs offer the most effective prevention method. Tests include colonoscopy, which allows doctors to view the entire colon and remove precancerous polyps before they become malignant. Fecal immunochemical tests and flexible sigmoidoscopy provide alternatives. Screening typically begins at age 45 to 50, though people with family histories may start earlier.
Lifestyle changes reduce risk substantially. These include eating more fiber, fruits, and vegetables; limiting red and processed meats; exercising regularly; maintaining a healthy weight; limiting alcohol; and quitting smoking. Early detection through screening dramatically improves survival rates, making regular screening essential for adults in the recommended age groups.