Risk Factors and Causes of Colorectal Polyps

Colorectal polyps develop as a result of abnormal tissue growth in the lining (mucosa) of the colon or rectum. Risk factors for colorectal polyps include the following:

  • Age (more common in patients over the age of 50)
  • Alcohol use
  • Cigarette smoking
  • Diabetes
  • Diet high in fat and low in fiber
  • Gender (slightly more common in men)
  • History of inflammatory bowel disease (IBD; e.g., ulcerative colitis, Crohn's disease)
  • Overweight/obesity
  • Personal or family history of colorectal polyps or colorectal cancer
  • Previous radiation therapy (e.g., to treat testicular cancer or prostate cancer)
  • Sedentary lifestyle

Polyposis syndromes are rare genetic (inherited) disorders that cause colorectal polyps and increase the risk for colorectal cancer. Types of polyposis syndromes include the following:

  • Cowden disease (causes multiple slow-growing polyps)
  • Familial adenomatous polyposis (FAP; characterized by the formation of hundreds to thousands of colorectal polyps)
  • Gardner's syndrome (also can cause bone and soft tissue tumors)
  • Hereditary nonpolyposis colorectal cancer (HNPCC) syndrome (also called Lynch syndrome; increases the risk for several types of cancer)
  • Juvenile polyposis (occurs in infants; can cause rectal bleeding)
  • Peutz-Jeghers syndrome (also causes polyps in the small intestine and increased pigmentation of the skin of the lips, fingers, and toes)
  • Turcot syndrome (also causes malignant brain tumors)

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 28 Feb 2008

Last Modified: 08 Sep 2015