Has your doctor told you that you need a colonoscopy, an EGD, or a capsule study?
Whatever one it is, you may have left the appointment with a procedure on the calendar and a few questions about what happens next.
Why do I need this test? What should I expect? Are there other options?
It’s easy to get these procedures mixed up. They all use a camera, but they look at different parts of your digestive tract, and they each have different capabilities. Your doctor’s recommendation depends on what they need to see, where they need to look, and whether they may need to treat something along the way.
Once you understand the differences in these three procedures, the recommendation usually makes a lot more sense.
What’s the difference between an EGD, colonoscopy, and capsule endoscopy?
EGD: examines the upper digestive tract.
Colonoscopy: examines the colon and rectum.
Capsule endoscopy: examines the small intestine, the long middle stretch the other two can’t fully reach.
Overview of the differences:
| EGD (upper endoscopy) | Colonoscopy | Capsule endoscopy | |
| What it examines | Esophagus, stomach, first part of small intestine | Colon and rectum | Mainly the small intestine |
| How it’s done | Thin scope through the mouth | Thin scope through the rectum | You swallow a camera capsule |
| Prep | Fasting beforehand | Bowel prep | The day before the exam, eat breakfast and lunch before noon. After noon, have only clear liquids until 10:00 p.m., then nothing by mouth. |
| Sedation | Typically | Typically | None |
| Can take samples or treat | Yes | Yes | No |
| Need a driver | Yes, if sedated | Yes, if sedated | No |
Your digestive tract, in three sections
It helps to picture your digestive system in three parts:
- The upper tract: your esophagus, stomach, and the first part of your small intestine
- The small intestine: a long, winding section in the middle
- The lower tract: your colon and rectum
Each procedure targets a different part of your digestive tract. Knowing what part to examine is the starting point for deciding which procedure makes sense for you.
Colonoscopy: a full look at the colon
During a colonoscopy, your specialist uses a thin, flexible scope with a camera to examine your entire colon and rectum.
It’s commonly recommended for:
- Colorectal cancer screening
- Blood in your stool
- Changes in bowel habits that don’t go away
- Ongoing diarrhea without a clear cause
- Unexplained anemia
- Follow-up after polyps or monitoring for inflammatory bowel disease
What sets a colonoscopy apart is that it can do more than look. Your specialist can remove polyps and take tissue samples during the same procedure.
That’s a big reason colonoscopy plays such an important role in colorectal cancer screening. It can find precancerous growths and remove them during the same visit. Other screening options are available, including stool-based tests. If one of those tests comes back positive, though, you’ll generally need a colonoscopy to take a closer look.
What to expect: You’ll need to complete a bowel prep the day before. You’ll typically receive sedation during the procedure and will need someone to drive you home afterward.
EGD: a closer look at the upper tract
EGD stands for esophagogastroduodenoscopy, which is why most people simply call it an EGD or upper endoscopy.
Your specialist guides a thin scope through your mouth to examine your esophagus, stomach, and the first part of your small intestine.
It’s commonly recommended for:
- Heartburn or reflux that doesn’t improve with treatment
- Trouble swallowing or the feeling that food is stuck
- Persistent upper abdominal pain, nausea, or vomiting
- Signs of bleeding in the upper digestive tract
- Suspected celiac disease
Like a colonoscopy, an EGD allows your GI specialist to take tissue samples and treat certain problems during the procedure. That might include stopping a bleed or gently stretching a narrowed area of the esophagus.
What to expect: You’ll need to avoid food and drink for a set period beforehand. You’ll typically receive sedation during the procedure and will need someone to drive you home afterward.
Capsule endoscopy: reaching the small intestine
With capsule endoscopy, you swallow a capsule about the size of a large vitamin. Inside is a tiny camera that takes thousands of pictures as it moves through your digestive tract. The images are sent to a recorder you wear, and the capsule passes naturally through your body.
The small intestine is long and winding, and most of it sits beyond the reach of a standard scope. The capsule can see the areas that other scopes can’t easily reach.
It’s commonly recommended for:
- Bleeding or iron-deficiency anemia when an EGD and colonoscopy haven’t found the source
- Evaluating suspected Crohn’s disease in the small intestine
- Looking for tumors or polyps in the small intestine
So why not use the capsule for everything?
This is one of the questions patients ask most often, and it makes sense. No scope. No sedation. Why not start there?
The biggest limitation is simple: a capsule can look, but it can’t do anything about what it finds.
It can’t take a tissue sample, remove a polyp, or treat a source of bleeding. If it finds something that needs attention, you’ll likely need another procedure to address it.
For the colon and upper digestive tract, a traditional scope can often find a problem and treat it during the same visit.
A capsule also isn’t right for everyone. If you have a known or suspected narrowing in your intestine, there’s a chance the capsule could get stuck. Your specialist may recommend a preliminary test to make sure the capsule can pass safely.
How your GI specialist decides where to start
No single test fits every digestive problem. Your specialist is looking at a handful of things to decide where to start.
Where are your symptoms pointing? Heartburn and trouble swallowing point toward the upper digestive tract. Changes in bowel habits may point toward the colon. Bleeding with no obvious source may mean your specialist needs to look farther into the small intestine.
Is this screening, diagnosis, or treatment? A routine colorectal cancer screening has a different goal than figuring out what’s causing new symptoms. The reason for the procedure helps determine which one makes sense.
Will you need a tissue sample or treatment? If your specialist will likely need to take a biopsy, remove a polyp, or treat a problem, a scope may make more sense than a capsule.
What have earlier tests shown? Previous procedures, lab work, and imaging can help narrow the search. Capsule endoscopy, for example, often comes after an EGD and colonoscopy haven’t found the source of ongoing bleeding or anemia.
What’s safest for you? Your medical history, medications, and any previous abdominal surgeries can all factor into the decision.
Sometimes the answer is more than one procedure
It’s not unusual to need more than one procedure to get a clear answer.
An EGD and colonoscopy are often performed on the same day, so you only have to go through sedation once. If both come back clear but symptoms such as bleeding or anemia continue, a capsule study may be the next step.
That doesn’t necessarily mean the first tests missed something. It means your GI specialist is looking at the problem from another angle and moving to an area the first tests couldn’t fully reach.
Depending on your symptoms, your specialist may also recommend other tests, such as breath testing, endoscopic ultrasound, or ERCP.
Questions worth asking at your appointment
You don’t have to know which procedure you need before you walk into the appointment. That’s your GI specialist’s job. You should, however, feel comfortable asking why they’re recommending it.
A few good questions to ask:
- Why is this procedure the right one for me?
- What are you looking for or trying to rule out?
- What happens if you find something?
- How do I prepare?
- Will I need someone to drive me home?
Understanding the reason behind the recommendation can make the process feel much less uncertain.
Frequently asked questions about these procedures
Can capsule endoscopy replace a colonoscopy?
Not for routine colorectal cancer screening. A colonoscopy lets your specialist examine the colon directly, remove polyps, and take tissue samples in the same procedure. A capsule can’t do those things.
Will I be awake during the procedure?
Your care team typically performs EGD and colonoscopy with sedation and will explain what to expect beforehand. Capsule endoscopy doesn’t require sedation. You swallow the capsule and go about your day while it takes pictures as it moves through your digestive tract.
When should I start colorectal cancer screening?
The American Cancer Society recommends that adults at average risk begin colorectal cancer screening at age 45. If you have a family history of colorectal cancer or symptoms that need to be evaluated, your specialist may recommend starting earlier.
Do I get a say in which procedure I have?
You definitely should be part of the conversation. Your GI specialist should be able to explain what they’re looking for, why they’ve recommended a particular procedure, and what the next steps would be if they find something.
The goal isn’t simply to choose a test. It’s to choose the test that’s most likely to give you a clear answer while keeping you as safe and comfortable as possible.
Get answers and stop guessing
If you’ve been dealing with digestive symptoms that won’t go away, you don’t have to keep guessing what’s causing them. The gastroenterologists at Consultants in Gastroenterology have offices in West Columbia and Northeast Columbia, and we can help you understand what’s going on and what to do next.
Whether you’re dealing with new symptoms or something you’ve been living with for years, we’ll listen, evaluate your symptoms, and help you find a path forward.
To schedule an appointment with one of our gastroenterologists, call our office at (803) 794-4585 or request a visit online. We look forward to caring for you.