The colonoscopy procedure in the office and the hospital are identical. However there are certain reasons why you would want to get the procedure done in one or the other. When at all possible you should try to get it done in a office. This is because it is not only a common environment for the physician it is also significantly less expensive. Not only is it less expensive in the hospital, you will only have a single bill instead of multiple ones.
This is because in a hospital you get billed by the doctor, billed by the hospital, and billed by the anesthesiologist. In a office setting, the doctor bills you only once, which includes the price of using facilities, getting the procedure done, and the use of a local anesthesiologist. The price of getting the procedure done in the office can be thousands of dollars less, then getting it done in the hospital.
However there are certain times when a hospital procedure is more suitable. Sometimes certain insurance companies will only cover getting the procedure done in the hospital which makes it significantly cheaper then paying upfront. Also anyone that is at high risk for developing problems during the procedure will need to be in a hospital setting. This makes it significantly safer, and may be required for in patients.