It is an examination of the last one third of your large intestine, including your rectum and the last part of your colon. A sigmoidoscopy should be done once every three to five years, beginning at age 50. For those who are at a higher risk of colorectal cancer due to a family history of colorectal cancer, polyposis or ulcerative colititis, a sigmoidoscopy may be recommended as early as age 35. A sigmoidoscopy may be done as a follow-up procedure after an abnormal digital rectal examination or after a positive fecal occult blood test. It can also pinpoint the source of some types of rectal bleeding or other symptoms related to the lower digestive tract.
Colorectal cancers are the third most common cancers in men and women.
An estimated 130,200 new cases of colon and rectal cancers and 56,300 deaths will occur in the year 2000. Signs and symptoms of colon or rectal cancer are rectal bleeding, blood in the stool or a change in bowel habits. The fecal occult blood test, also called a stool guaiac or hemoccult test, is a screening test used to detect colorectal cancer, especially when the cancer is in its early stages and causes no other signs or symptoms. The fecal occult blood test checks stool samples for traces of blood that cannot be seen with the naked eye. It involves a chemical test of three consecutive stool samples.