Carcinoma of colon is the most common cancer of GIT. Peak incidence in 70-80, with 7% under age of 40. 30% of the cases are associated with polyps. Rectal cancer is more common in males, while colonic cancer is more common in females. Risk factors for colorectal cancer are aging which is the dominant risk factor, dietary factors (High animal fat food, deficiency of vits A,C, & E, and selenium), alcohol increases colonic cancer, obesity, and smoking. Patients with familial adenomatous polyposis syndrome 100% will develop the cancer, other premalignant conditions are adenoma, hamartomas, ulcerative colitis > crohns disease, and schistosomiasis. Symptoms of colonic cancer are anemia, obstruction, dyspepsia, and appendicitis. Symptoms of rectal cancer are bleeding, altered bowel habit, tenesmus, pain, and bladder symptoms. Treatment is mostly by surgical resection with or without chemotherapy.