The colon must be thoroughly cleansed before performing colonoscopy. Consequently, for two or more days before the procedure, considerable preparation is necessary to clear the colon of all stool. The patient is asked to refrain from eating any solid food for 24–48 hours before the test.
Two days before your colonoscopy, you may eat light meals that include fat-free clear soups; small portions of skinless chicken or turkey; fish; white bread; eggs; plain noodles; plus any clear liquids.
24 hrs before, only clear liquid such as juices, broth, and gelatin are allowed. Red or purple juices should be avoided, since they can cause coloring of the colon that may be misinterpreted during the colonoscopy.
The patient is advised to drink plenty of water to avoid dehydration. A day or two before the colonoscopy, the patient is prescribed liquid, tablet, and/or suppository laxatives by the physician. In addition, commercial enemas may be prescribed. The patient is given specific instructions on how and when to use the laxatives and/or enemas.
After breakfast on the day before your examination, you will be following a clear liquid diet. You can eat any of the following:
Broth or bouillon
Black tea or coffee (you may have sugar)
White grape juice
Plain Jell-O (gelatin)
You may not have any solid food, including butter, cream, fruit, vegetables, seeds, or nuts. Eat or drink nothing that is dark red or purple, such as in juices, Jell-O, or popsicles.
On the morning of the colonoscopy itself, the patient is not to eat or drink anything. Unless otherwise instructed by the physician, the patient should continue to take all current medications. However, vitamins with iron, iron supplements, or iron preparations should be discontinued for a few weeks prior to the colonoscopy because iron residue in the colon can inhibit viewing during the procedure.
These preparatory procedures are extremely important to ensure a thoroughly clean colon for examination.