Smoking
The lung is not the only organ smoking affects. Many people might not be aware that smoking is also closely associated with colorectal adenomatous polyps. How could it happen? Cigarettes contain harmful chemicals and toxins. When people inhale these substances, free radicals are absorbed by colorectal mucosa and trigger DNA adducts formation and aberrant crypt foci (acquired gene mutations). With the gradual development, minute colorectal adenomas (<0.5 cm) come into being, and some adenomas may grow to larger adenomas (>1 cm). Smoking could also cause flat adenomas. These polyps have a flat top, making them very hard to detect. Some colorectal adenomatous polyps may become cancerous, leading to rectal colon cancer eventually. [4]
