Although a colonoscopy is one of those procedures that everyone dreads, it is the most effective way of preventing colon cancer. A day or two of discomfort could — quite literally — save your life.

If you’re concerned about the procedure itself being painful, you can take some comfort in knowing that, for most people, colonoscopies don’t hurt at all.

The Centers for Disease Control and Prevention (CDC) rank colorectal cancers as the third leading cause of cancer-related death in the U.S. One of the most effective tools for detecting colorectal cancer is a colonoscopy.

Colonoscopies are typically done by gastroenterologists, who specialize in conditions and issues related to the digestive tract.

Before the procedure starts, you’ll lie on your side on a table, either in a private room at an outpatient medical center or at the gastroenterologist’s office. Your doctor or a nurse will then give you medication, usually through an intravenous line, to make you sleepy.

Once you’re sedated, the doctor will insert a thin, flexible tube into your rectum. The tube is fitted with a tiny light and camera that allows the doctor to see any abnormalities, like polyps or ulcers, throughout your colon (large intestine).

If one or more polyps are present, the doctor will usually remove them with a looped wire that slips inside the tube.

Finding and removing any questionable polyps can cut your risk of colon cancer by as much as 40 percent, according to the Mayo Clinic.

The good news is that in most cases, you’ll be completely sedated for the entire procedure. When you wake up, the procedure will be over. Many people say they can’t even remember having a colonoscopy at all.

In countries outside the U.S., sedation is often optional, so if you want to be sure you’re asleep during the procedure, talk to your doctor in advance about the sedation options available to you.

A range of sedatives is available for a colonoscopy, from mild sedation to anesthesia. Many doctors administer one of the following sedatives before the procedure:

Research has shown that doctors may use different doses and medications based on age, gender, race, and drug use history.

If you have questions or concerns about the sedatives that will be used during your colonoscopy, be sure to ask your doctor for more information.

Every drug has potential side effects. If you want to know more about the risks and side effects of the medications you’ll be given, talk to your doctor when you schedule the procedure.

Some people may have a headache or feel nauseated after being sedated.

In general, people usually feel very sleepy after a colonoscopy. Someone will need to drive you home after the procedure because you’ll be too drowsy to drive.

Doctors recommend that you avoid driving or using machinery for at least 24 hours after a colonoscopy.

A small percentage of people may experience mild abdominal cramping, similar to gas pains, after a colonoscopy. This may last for about a day after the procedure.

The reason for this is because the doctor might have used a small amount of air to open up the colon to get a better view during the procedure. As this air moves through your colon, you could feel a bloated or gassy sensation.

If your doctor discovered an area of tissue that needed to be tested, they might have performed a biopsy. If you had a biopsy during your colonoscopy, you might notice mild discomfort or a small amount of bleeding afterward.

According to doctors at the Cleveland Clinic, the risk of bleeding is very low — less than 1 percent. If pain worsens or you notice a lot of bleeding, or if your abdomen feels hard and full, talk to your doctor right away.

It’s also important to talk to your doctor if you aren’t able to go to the bathroom or pass gas after a colonoscopy.

Some people may prefer not to receive sedatives or opioid medications, especially if they’re recovering from drug or alcohol addiction. If you’re scheduled for a colonoscopy and don’t want pain medication, here are some options:

  • Have an IV inserted before the procedure starts, so medical staff can start nonnarcotic pain relief medications quickly if you need them.
  • Request a noninvasive screening method, like Cologuard.
  • Check with your insurance provider to see if a screening CT scan could be used to detect any abnormalities.
  • Talk to your doctor about other options for screening and detection of colorectal cancers.

Colonoscopies aren’t usually painful because most patients receive a sedative before the procedure starts. The sedative makes you so sleepy that you usually don’t feel or remember anything of the procedure.

In places other than the U.S., sedation isn’t always offered for a colonoscopy, so you may want to talk to your doctor beforehand to be sure you understand your pain management options.

If your doctor introduced air into your bowel during the procedure, there’s a small chance you may feel some gas-like cramping after your colonoscopy.

If your doctor performed a biopsy, you may have mild discomfort the next day. If you do experience pain afterward, talk to your doctor.