Individuals who should undergo screening for colorectal cancer through lower gastrointestinal endoscopy:

• Individuals over 50 years old without waiting for symptoms
• Individuals with a family history of colorectal and bowel cancer without waiting for symptoms
• Changes in bowel movements, alternating between constipation and diarrhea, stool mixed with mucus, narrow stool, or smaller stool size
• Frequent constipation
• Unexplained weight loss
• History of inflammatory bowel disease, such as chronic colitis
• Black stool or stool with blood
• Previous detection of polyps in the intestinal wall during endoscopy
• Unexplained weight loss
• Previous colorectal cancer surgery within 1 year, 3 years, or 5 years