Normal Risk

• American Academy of Family Physicians --
• Individuals aged 50 years and older and those aged 40 years and older with a family history of early colorectal cancer should be screened for colorectal cancer with fecal occult blood tests, sigmoidoscopy, colonoscopy, or barium enema.

• American Cancer Society (ACS) and American Gastroenterological Association --
• Patients at normal risk should be screened with sigmoidoscopy every 5 years in combination with yearly fecal occult blood testing beginning at 50 years of age. Other recommended screening options beginning at age 50 include: colonoscopy every 10 years or double contrast barium enema every 5 to 10 years. The ACS further advises that digital rectal examination be performed along with the endoscopic or radiological procedure.

• American College of Obstetricians and Gynecologists --
• Patients at normal risk should be screened with sigmoidoscopy every 3 to 5 years beginning at 50 years of age.

• American College of Physicians --
• Men and women should be offered flexible sigmoidoscopies every 10 years from 50 to 70 years of age. In most settings and for most people, this strategy will provide the best balance of benefits and harms, logistic feasibility, and costs. In settings where it is logistically feasible and cost is reasonable, persons who want to achieve the maximum protection against colorectal cancer should be offered colonoscopy every 10 years from 50 to 70 years of age. In some settings, air-contrast barium enemas every 10 years from 50 to 70 years of age might be logistically preferable to colonoscopies, and some patients might prefer that procedure. For persons who decline these options, annual fecal occult blood testing should be offered.

• Canadian Task Force on the Periodic Health Examination --
• There is insufficient evidence to support the inclusion or exclusion of sigmoidoscopic or colonoscopic screening of asymptomatic individuals over 40 years of age in the periodic health examination.

• US Preventive Services Task Force --
• Screening for colorectal cancer is recommended for all persons 50 years of age or over. Sigmoidoscopy and fecal occult blood testing are effective methods of screening. There is insufficient evidence to determine which of these methods is preferable or whether the combination of both methods produces greater benefit than either method alone. There is insufficient evidence to recommend a periodicity for sigmoidoscopy screening.

Increased Risk

• All major authorities --
• Patients at increased risk of colorectal cancer should consider more intensive screening. What constitutes increased risk and the nature and frequency of recommended screening differs slightly among the authorities.

• American Cancer Society --
• For patients having a first-degree relative with a history of colorectal cancer at 55 years of age or younger, the entire colon and rectum should be examined with colonoscopy or air-contrast barium enema every 5 years beginning at 35 to 40 years of age. Members of families with a history of familial adenomatous polyposis should receive earlier screening utilizing flexible sigmoidoscopy. Members of families with a history of hereditary nonpolyposis colorectal cancer require earlier and more intense surveillance utilizing colonoscopy. Individuals with inflammatory bowel disease are at exceptionally high risk and require individualized treatment. Patients under age 55 years with a first-degree family member with a history of colorectal cancer are at increased risk and may need earlier and more frequent examinations. People with a history of breast, ovarian, or endometrial cancer are at some increased risk but should follow screening recommendations for normal-risk patients.

• American College of Obstetricians and Gynecologists --
• Colonoscopy should be a part of primary preventive care for individuals with a personal history of inflammatory bowel disease or colonic polyps, or a family history of familial polyposis coli, colorectal cancer, or cancer family syndrome.

• American College of Physicians --
• Individuals who have one or more first-degree relatives with colorectal cancer should be offered colonoscopy at 40 years of age and at least every 10 years thereafter.

• American Gastroenterological Association --
• Individuals with a first-degree relative who has had colorectal cancer or an adenomatous polyp should be screened beginning at age 40 years. Gene carriers for familial adenomatous polyposis (FAP) or people with a family history of FAP whose gene carrier status is indeterminate should be offered yearly flexible sigmoidoscopy beginning at puberty to see if they are expressing the gene. If polyposis is present, they should begin to consider when they should have colectomy. People with a family history of hereditary nonpolyposis colorectal cancer should be offered an examination of the entire colon (via colonoscopy or double contrast barium enema, preferably with sigmoidoscopy) every 1 to 2 years starting between the ages 20 and 30 years and every year after age 40 years. In patients with long-standing, extensive inflammatory bowel disease, surveillance colonoscopy should be considered, along with the extent and duration of the disease, as a guide to when or if colectomy should be considered. A common practice is to perform surveillance colonoscopy every 1 to 2 years beginning after 8 years of disease in patients with pancolitis or after 15 years in those with colitis involving only the left colon.

• Canadian Task Force on the Periodic Health Examination --
• There is insufficient evidence to recommend for or against the inclusion or exclusion of sigmoidoscopy in the periodic health examination of asymptomatic individuals over 40 years old (including those with a family history of one or two relatives with colorectal cancer). There is fair evidence to exclude sigmoidoscopy from the periodic health examination of individuals with true cancer family syndrome; however, there is fair evidence for the inclusion of colonoscopy in the periodic health examination of individuals with true cancer family syndrome.

• US Preventive Services Task Force --
• In high-risk groups, there is insufficient evidence to recommend for or against early or frequent screening or the use of colonoscopy rather than sigmoidoscopy. However, early and frequent colonoscopy screening of patients with a family history of familial polyposis coli or cancer family syndrome or with personal histories of previous adenomatous polyps or colorectal cancer may be recommended on other grounds, including the increased risk of colorectal cancer and of lesions in the proximal colon.

1. Training:

Sigmoidoscopy should be performed only by or under the supervision of a trained examiner. Training should be obtained from an experienced endoscopist. Training may consist of diagnostic instruction with audiovisual materials, endoscopic models, and photo atlases, followed by patient demonstrations and successful completion of a number of supervised examinations.

2. Sigmoidoscope type:

Most authorities recommend use of a flexible sigmoidoscope (preferably 60 cm in length) rather than a rigid sigmoidoscope because of better patient acceptance and the ability to visualize lesions higher in the sigmoid colon.

3. Patient preparation:

Proper bowel preparation is essential for performance of an adequate screening examination. Recommendations for bowel preparation differ somewhat. The minimum preparation consists of administration of two enemas a few hours before examination.

4. Follow-up of abnormal results:

All authorities agree that patients found to have adenomatous polyps of 1 cm or larger need colonoscopic examination of the entire colon. Approximately 10% of individuals screened will have small tubular adenomas less than 1 cm in diameter. Controversy exists about whether patients with these lesions need colonoscopic follow-up in view of their low potential for malignancy.

5. Maintenance of competence:

Clinicians need to perform sigmoidoscopy routinely to maintain competence. Performing procedures only occasionally may lead to missed or inappropriate diagnoses and a high rate of complications.