Preparation
Some screening methods require more preparation than others. The 
indicates the test(s) requiring the least preparation.
Colonoscopy
- You must follow a clear liquid diet on the day before the test.
- You must drink 2 to 4 quarts of a mildly salty-tasting preparation and you may also need to take a laxative pill the evening before the test.
Virtual Colonoscopy
- You must follow a clear liquid diet on the day before the test.
- You must take a strong laxative in liquid and/or pill form the evening before the test.
- You may be asked to drink another liquid called contrast medium.
Flexible Sigmoidoscopy
- You must take one to two enemas before the procedure.
- In some cases, you might also need to take a laxative on the evening before the test.
Barium Enema
- You must take a laxative and use an over-the-counter enema before the test.
- You may also be asked to follow a clear liquid diet the day before the test.
FOBT
- Depending on the type of test, you may need to avoid red meat and certain fruits and vegetables for three days before and during the stool collection period.
- Your doctor may also suggest that you stop using aspirin or other anti-inflammatory medications during the stool collection period.
Stool DNA Test
- No preparation necessary.