A colonoscopy is a medical procedure involving the examination of the large bowel (colon) and the rectum. This is achieved by inserting a long, flexible tube, called a colonoscope, with a tiny camera through the anus to inspect the inner lining of the intestines. The procedure screens for colorectal cancer by identifying and removing precancerous growths called polyps, and diagnoses intestinal symptoms like unexplained bleeding or chronic diarrhea. While being “put under” suggests full unconsciousness, a form of sedation is almost always offered, though the depth varies based on the facility’s protocol and the patient’s health profile.
Standard Sedation Practices
Sedation is the standard of care for a colonoscopy to ensure patient comfort and maximize the procedure’s effectiveness. The primary goal is to minimize pain or discomfort, which often occurs as the scope navigates the colon’s natural bends and loops. Sedation helps the patient relax and remain still, allowing the gastroenterologist to safely and thoroughly examine the entire colon and remove any polyps.
The process begins with the insertion of an intravenous (IV) line, typically in the hand or arm, used to administer the medication. The sedative is usually given just before the procedure starts. Throughout the procedure, the patient’s heart rate, blood pressure, and oxygen levels are monitored by a dedicated care team.
Types of Anesthesia Used
The medications used in a colonoscopy range from making the patient drowsy to rendering them completely unconscious. Most facilities offer two primary levels of sedation.
Moderate Sedation
The lightest common option is moderate sedation, also referred to as conscious sedation, where the patient is awake but significantly relaxed. This level often uses a combination of a short-acting tranquilizer, such as Midazolam, and an opioid pain reliever, like Fentanyl, delivered through the IV. Under moderate sedation, the patient remains responsive and able to follow basic verbal commands. Patients often feel sleepy and have little to no memory of the procedure afterward.
Deep Sedation
Deep sedation is frequently managed by an anesthesia provider, such as a certified registered nurse anesthetist or an anesthesiologist. This approach is often called Monitored Anesthesia Care (MAC) and typically involves the drug Propofol. Propofol is a rapid-acting anesthetic that causes the patient to fall completely asleep, making them generally unresponsive. A key advantage of Propofol is its rapid elimination from the body, leading to a quicker recovery compared to other sedatives.
General Anesthesia
The deepest level, general anesthesia, is rarely used for routine colonoscopies but is reserved for specific cases. General anesthesia results in a state of full unconsciousness and requires the patient to have assistance with breathing, such as intubation. This may be considered for patients with complex medical issues, long or complicated procedures, or individuals who have had difficulty with lighter sedation previously.
The Choice to Remain Awake
While most patients choose sedation, having a colonoscopy with minimal or no medication is an option. This choice allows the patient to avoid side effects associated with anesthetic drugs, such as potential nausea or prolonged grogginess. A benefit of foregoing sedation is the ability to bypass the mandatory recovery period and resume normal activities, including driving, almost immediately after the procedure.
Patients who choose this path must be prepared for potential discomfort. The inflation of the colon with air and the navigation around the bends can cause cramping or a feeling of fullness. The procedure is typically shorter for unsedated patients, often taking only about 30 minutes, but it requires the patient to remain relaxed and cooperative. Discussing this preference with the healthcare team beforehand is important to ensure the facility and physician are prepared to perform the colonoscopy without sedatives.