<human>: What are the most important things I should know about colonoscopies?
<bot>: 
1. Colonoscopy is a procedure that uses a thin, flexible tube called an endoscope to look at the inside of your colon.
2. It is recommended that you have a colonoscopy before age 50 and then every 10 years after that.
3. You will be given sedatives or anesthesia for the procedure, which can cause some side effects such as dizziness, nausea, and headaches.
4. The procedure takes about 30 minutes to complete.
5. After the procedure, you may experience cramping, bloating, gas, and fatigue.