Colonoscopy Preparation & Headaches

A colonoscopy is used to detect any changes or abnormalities in your colon and rectum, and it is considered highly effective for colon cancer screening 1. You must take time to prepare; doing so makes the test easier to perform and ensures the most accurate results. Side effects can occur, one of which stems from the medication given to sedate you during the procedure.

The Procedure

An outpatient procedure, a colonoscopy enables your doctor to view your entire colon by inserting a long, flexible tube inside your rectum. A small video camera is attached at the end and can detect abnormal tissue, or polyps. Polyps are small clusters of cells that have the potential of becoming cancerous. During the procedure, your doctor usually removes these and can take samples of abnormal tissue. If the polyps are found to be cancerous, a treatment plan is devised.


Your doctor must have a clear view of your colon; for this reason, your bowel must be clean and free of residue. Failure to follow your preparation directions properly can result in a repeat of your colonoscopy. Your physician may prescribe a special diet the day before. Although no solids are allowed, you can have clear liquids such as water, tea and coffee. You must leave out the milk and cream, however. Broth and carbonated beverages are both permitted. Laxatives, either in pill or liquid form, are the norm as well. This expedites the cleansing process. An over-the-counter enema may also be necessary, explains It may be necessary to stop certain medications for a short period of time, but your doctor will advise you of this approximately one week before your procedure.

Preparation Side Effects

Nausea can result depending on the liquid your doctor prescribes for bowel cleansing. Taking small sips, and waiting 30 minutes between each, may help. Irritation around your anus may occur due to the number of bowel movements you have. Using baby wipes in place of toilet paper may help. Apply petroleum jelly or rash ointment to this area as well. Soak in a bathtub for approximately 10 or 15 minutes and reapply the ointment.


Due to the nature of your procedure, your doctor usually gives you a sedative to relieve your anxiety and kill the pain. The medication also induces amnesia so you don't recall the events. The two most commonly used medications are Versed and Propofol, according to Colon Cancer Resource. Although lists headaches as a rare side effect of Versed, some patients do experience this after their colonoscopy 2. It is combined with narcotics, such as Demerol, Valium and Fentanyl. Propofol works without narcotics and is much more powerful, but some insurance companies won't cover its cost.