Why Do People Get a Colonoscopy for Ulcerative Colitis?
Ulcerative colitis is a type of inflammatory bowel disease that causes inflammation and sores to form in the large intestine and rectum. It happens when the body's immune system mistakenly attacks the lining of the colon, leading to swelling and irritation. This can cause symptoms like diarrhea, blood in your stool, stomach cramps, or an urgent need to poop.
To diagnose ulcerative colitis, doctors use an endoscope – a thin, flexible tube with a camera attached – to examine the colon. They might perform a colonoscopy, which provides a full view of the colon, or a sigmoidoscopy, which focuses on the lower part. During the procedure, they take a small tissue sample (called a biopsy) to check for inflammation and other signs of the disease under a microscope. While additional tests can rule out other types of inflammatory bowel disease, a biopsy is the only way to confirm an ulcerative colitis diagnosis with certainty.
If you've already been diagnosed with ulcerative colitis, your doctor will recommend regular colonoscopies to monitor any damage to your large intestine and screen for colon cancer. While medications can help manage symptoms, ulcerative colitis has no cure. People with inflammatory bowel disease have a slightly higher chance of getting colon cancer, but routine colonoscopies can detect changes in the large intestine early, often before cancer can grow.
How to Prepare for a Colonoscopy for Ulcerative Colitis
To give doctors a clear view of your colon during a colonoscopy, your large intestine needs to be completely empty. This will require some preparation in the days leading up to the test. Your doctor will give you specific instructions, but you’ll likely need to adjust what you eat and possibly stop taking certain medications for up to a week before the procedure. Here's what those adjustments might look like:
Four days before your colonoscopy: Stop taking any medications that contain iron (look for "iron," "ferrous," "ferric," or "feredetate" on the label). You can continue taking all other medications as usual and eat and drink normally.
Three days before your colonoscopy: Stop taking any medications with codeine phosphate (used to treat pain, coughing, and diarrhea) or contain loperamide (used to treat diarrhea). Keep taking all of your other medications as usual, and you can still eat and drink normally.
Two days before your colonoscopy: Drink plenty of fluids – aim for eight to 10 glasses of water each day – and start eating smaller meals. Avoid high-fiber foods like fruits, veggies, and whole grains, as well as nuts and seeds, fried foods, and alcohol. Instead, choose lean meats and fish, white bread or pasta, eggs, milk, tofu, or peeled potatoes.
One day before your colonoscopy: Take your regular medications unless your doctor says otherwise. If you take morning medication, try to take it before 10 a.m. Evening medication should be taken after 9 p.m. You can have a light breakfast, but after that, you'll need to switch to clear liquids for the rest of the day. These include water, fizzy drinks, or clear soups and stocks. Aim for eight to 10 glasses of liquid, and do not drink alcohol. You'll also take a laxative to flush out any remaining waste. This will cause frequent trips to the bathroom, so it's best to stay near a toilet for several hours. The procedure is usually scheduled for the following morning.
Saraswathi Lakkasani, MD, a gastroenterologist with HCA Virginia and a spokesperson for the American Gastroenterological Association, says that patients with ulcerative colitis – who often have belly pain, diarrhea, or blood in their stool – may have a harder time tolerating the laxative preparation for a colonoscopy. To make it a bit easier, many doctors offer a choice between a liquid or tablet laxative. Laxatives may make you feel bloated, dehydrated, or a bit sore around your anus when you go to the bathroom. Drinking plenty of water and using a protective cream like zinc can help ease these symptoms.
Lakkasani says that there are no special colonoscopy preparations specifically for people with inflammatory bowel disease.
What to Expect During a Colonoscopy for Ulcerative Colitis
A colonoscopy can be done under general anesthesia, where you’ll be asleep, or with sedation, which keeps you awake, but relaxed – you may not even remember the procedure afterward. These medications are given through an IV in your arm. Once they take effect, your doctor will insert a colonoscope – a thin, flexible tube with a small camera that sends images to an external monitor – into your rectum. They'll then guide it through your large intestine to check for signs of inflammation or other potential issues. As they advance the scope, they’ll pump a small amount of air into your colon to gently expand it, giving them a clearer view of its lining.
During the procedure, your doctor may take tissue samples (called biopsies) from your large intestine using a special tool that can be passed through the colonoscope.
Once the scope reaches the end of your large intestine, the doctor will slowly withdraw it, carefully examining the colon again on the way out. You won’t feel any pain during the procedure, but some people have a bit of gas or pressure because of the air that’s used to inflate the colon.
The entire procedure usually takes 30 minutes to an hour. Afterward, your doctor will review the results with you in the recovery room. You’ll receive the formal report by mail or electronically. If a tissue sample was taken, you can discuss the findings at a follow-up appointment.
Recovering After a Colonoscopy for Ulcerative Colitis
After your colonoscopy, you’ll be taken to a recovery area while the sedation wears off. During this time, nurses will monitor your blood pressure, temperature, and heart rate to make sure there are no complications. You may feel groggy or tired for the rest of the day, so it’s important to have someone there to drive you home. Mild bloating, gas, or cramping are normal after a colonoscopy, but these symptoms should pass within a few hours. "If you feel gassy or like going to the bathroom, don’t hesitate to do so," Lakkasani says. Going for a short walk or drinking peppermint tea can also help. If your doctor took tissue samples during the procedure, it's normal to have some light bleeding for a few days.
If you had sedation, you should avoid drinking, driving, taking sleeping pills, or making any important decisions for 24 hours. Most people can return to work and their usual activities the next day. Lakkasani recommends starting with a light meal after the procedure, but you should also be able to eat normally within a day. If you have cramps or gas after your colonoscopy, try to avoid high-fiber foods, since they can make your symptoms worse. It's best to take it easy and follow any specific instructions from your doctor, especially if you have ulcerative colitis flare-ups.
If you have pain, heavy bleeding, or a fever after the procedure, contact your doctor right away.
How Often to Get a Colonoscopy for Ulcerative Colitis
Regular colonoscopies are an important way for doctors to monitor ulcerative colitis and check for early signs of colon cancer, which is slightly more common in people with the condition. Colonoscopies can catch cancer early – sometimes even before it develops – when it's easier to treat and cure.
If you've already been diagnosed, how often you’ll need a colonoscopy depends on how severe your ulcerative colitis is and whether there are any other health concerns. Generally, most people get their first screening eight years after receiving their diagnosis. Your doctor may recommend a screening every year, every three years, or every five years after that.
Lakkasani says that the part of the colon most affected by ulcerative colitis can influence how often you need a colonoscopy. If it mainly affects the right side of your colon, your chances of getting colon cancer are higher. But if it mainly affects the left side, they're lower. "If ulcerative colitis involves only the rectum, your risk is similar to the general population," she says.
It's important to keep up to date with screenings. "Even with mild ulcerative colitis, there's still a higher risk of cancer," Lakkasani says. "Some people think, 'I have no symptoms, just mild inflammation, and I feel fine without treatment,' but that’s not correct."
Takeaways
If you have ulcerative colitis, a colonoscopy is an important tool for diagnosing and monitoring your condition. It's also the best way to screen for colon cancer, which is slightly more common in people with ulcerative colitis. During the procedure, a doctor uses a thin, flexible tube with a camera to examine your colon. While the procedure itself isn't painful, you may have mild cramping or bloating afterward. How often you need a colonoscopy depends on how severe your condition is, but most people have one every one to five years. Be sure to follow your doctor's advice on how often you should get screened, and reach out if you have any complications after the procedure.
Colonoscopy for Ulcerative Colitis FAQs
When do you need a colonoscopy for ulcerative colitis?
How often you need a colonoscopy depends on how severe your ulcerative colitis is. Most people have their first screening eight years after diagnosis, then continue with follow-ups every one to five years.
Does everyone with ulcerative colitis need a colostomy bag?
No. Only 30% of people who have ulcerative colitis will eventually need a colostomy bag.
What is the best diagnostic test for ulcerative colitis?
A colonoscopy with a biopsy, where a small tissue sample is taken from your large intestine, is the only way to confirm an ulcerative colitis diagnosis.
