Diagnostic Tests Explained
Not sure what to expect during an imaging exam or endoscopy? Here’s a clear, step-by-step guide to the five most common procedures in UC.
CT Scan
Quick imaging using X-ray beams
Physicians may order a CT scan to examine parts inside your body, including soft tissues like organs, but also bones, blood vessels, or even the brain. A CT scan uses X-ray beams to create pictures. The scan can take up to 30 minutes and isn’t painful at all. In some cases, you might need an IV (a small tube inserted into your vein) before the scan starts, as you’ll receive a contrast agent that helps differentiate different soft tissues.
- You’ll lie on a comfortable table with a blanket.
- The table will slowly move into a large, round machine (shaped like a donut).
- The only challenge is staying still, but pillows will be provided to help limit movement.
- If you want, someone can stay with you in the CT room during the scan.
Video Capsule Endoscopy (“Pillcam”)
A tiny camera in a swallowable capsule
With a capsule endoscopy, gastroenterologists examine the small intestines — which can’t be fully examined during a gastroscopy or colonoscopy. The procedure is safe and painless. Older children and teens can usually swallow the capsule (about the size of a large jellybean or vitamin). If swallowing the capsule is difficult, gastroenterologists can insert it during a gastroscopy.
- You’ll likely need to follow a clear liquid diet and drink a special bowel prep drink to clear out all the stool from your small intestines.
- The capsule contains a camera that takes pictures as it moves through your small intestines.
- The pictures are recorded by a device you wear around your waist (like a fanny pack).
- After swallowing the capsule with water, you can resume most regular activities — but no sport or strenuous activity while wearing the recorder, since impact or sweat can affect it.
- After a couple of hours, you can eat a light meal again.
- About 8 hours later, you can usually remove the recorder, and your physician can start reviewing the pictures.
- The capsule will pass naturally with your stool within 1–3 days — don’t worry, you usually won’t need to collect it.
Ultrasound
Sound waves create images — no radiation
An ultrasound is an exam that creates images of your organs, tissues, and other structures inside your body by sending sound waves into it. You don’t need any specific preparation, but you might have to fast for a few hours before the exam.
- You’ll need to remove your clothes from the area being examined.
- The technician will apply gel to the area to reduce air between your body and the ultrasound device (the “transducer”) for clearer images.
- During the exam, the technician moves the transducer around, sending sound waves into your body.
- The transducer also collects the echoes, which are instantly displayed as images on a screen.
Gastroscopy
A camera exam of your upper GI tract, while you’re asleep
Gastroscopy, also called OGD (oesophagogastroduodenoscopy) or EGD (esophagogastroduodenoscopy), is a procedure that allows gastroenterologists to examine the inside of your upper gastrointestinal tract. The upper gastrointestinal tract includes your esophagus, stomach, and the first part of the small intestines (called the duodenum). For a gastroscopy, the only preparation needed is to avoid food or drinks, typically starting the night before the procedure.
- Before the procedure, you’ll meet with an anesthesiologist who will put you to sleep during the gastroscopy.
- To do this, a needle (IV) will be inserted into one of your arms to give the anesthetics.
- Once asleep, the gastroenterologist will insert a long, bendable tube with a light and a camera through your throat, down the esophagus, and into your stomach and duodenum.
- As the tube moves through, real-time images will appear on screen allowing the physician to see if and where there is any inflammation.
- The physician may also take tissue samples (“biopsies”) for further examination in a laboratory.
- A gastroscopy usually takes about 20 minutes.
- When you wake up, take it easy for the rest of the day and allow your body to recover. Normal activities can resume the next day.
- If you drive, keep in mind you aren’t allowed to drive home — arrange for someone to pick you up.
- You might feel a bit sore in the throat or bloated for a few hours, but these symptoms will go away soon.
Colonoscopy
A camera exam of your large intestines, while you’re asleep
A colonoscopy is similar to a gastroscopy, but instead of examining the upper gastrointestinal tract, it focuses on the large intestines and the last part of your small intestines (terminal ileum). During the procedure, a tube is inserted into the anus and moved through the rectum, descending colon, transverse colon, and ascending colon until it reaches the terminal ileum.
- To examine the inside of your colon, it must be completely empty.
- Your medical team will likely ask you to stop eating certain hard-to-digest foods like raw or dried fruits, foods with seeds (e.g., whole grain bread, tomatoes, cucumber).
- The day before the procedure, you may also need to stop drinking milk or eating dairy products.
- That same day, you’ll begin the bowel washout, which involves drinking a special bowel prep solution starting in the afternoon. This will cause you to use the restroom a lot as it clears all the stool from your digestive system. You can mix the bowel prep with certain drinks — ask your provider which ones.
- Once you start the washout, plan to stay home, as you’ll be using the restroom a lot for several hours.
- Your large intestines should be empty once your stool looks like clear chamomile tea or apple juice without any solid pieces.
- After finishing the bowel prep, you must fast and avoid eating or drinking.
- If you take medication, discuss with your medical team when and if you should take it on the day of your procedure.
- Before your colonoscopy starts, you’ll meet with an anesthesiologist who will insert a needle into your arm to inject anesthesia.
- Once you are asleep, the gastroenterologist will begin the colonoscopy, during which several tissue samples (“biopsies”) will be taken, or polyps removed for further examination in a laboratory.
- You won’t feel any of this, as you’ll be fully sedated during the procedure.
- If you are an outpatient, you can go home — but someone must pick you up, and you won’t be allowed to drive since the sedative will still be in your system.
- Take it easy for the rest of the day, avoid driving or operating machinery, and eat light meals.
- You might feel a little bloated or gassy and need to pass gas, but these symptoms will go away within a few hours.