Key Pointers
- The small intestine is one of the most difficult parts of the digestive tract to examine using standard procedures.
- Regular upper endoscopy and colonoscopy can only visualise certain sections of the digestive system.
- Specialised investigations such as capsule endoscopy and balloon-assisted enteroscopy may be used to evaluate the small intestine.
- These tests may help identify sources of bleeding, inflammation, polyps, or other abnormalities.
- Persistent digestive symptoms may warrant further assessment when routine investigations are inconclusive.
Why Is the Small Intestine Difficult to Examine?
When people think about digestive investigations, they often assume that a standard endoscopy can see the entire digestive tract. In reality, different procedures are designed to examine different areas, and there is one section that can be particularly challenging to access—the small intestine.
The small intestine sits between the stomach and the large intestine and measures several metres in length. Because of its size, shape, and location, much of it cannot be reached using conventional endoscopic procedures.
This presents a challenge when symptoms suggest that a problem may be originating from this part of the digestive system.
What Areas Can Regular Endoscopy and Colonoscopy Examine?
Understanding the limitations of standard procedures helps explain why additional investigations are sometimes necessary.
An upper endoscopy (gastroscopy) allows doctors to examine:
- The oesophagus
- The stomach
- The first part of the small intestine (duodenum)
A colonoscopy allows doctors to examine:
- The colon (large intestine)
- The rectum
- A small portion of the lower small intestine in some cases
While these procedures provide valuable information, a large section of the small intestine remains beyond their reach.
If symptoms persist despite normal findings on these tests, doctors may consider other methods to evaluate the area in between.
What Symptoms Might Suggest a Problem in the Small Intestine?
Many digestive symptoms can originate from the stomach or colon, but some may indicate that the small intestine requires closer evaluation.
This is particularly true when symptoms remain unexplained after routine testing.
Symptoms that may prompt further investigation include:
- Unexplained gastrointestinal bleeding
- Iron deficiency anaemia without an obvious cause
- Persistent abdominal pain
- Chronic diarrhoea
- Unexplained weight loss
- Suspected inflammatory bowel disease
- Ongoing digestive symptoms despite previous normal investigations
These symptoms do not necessarily mean a serious condition is present, but they may indicate the need for a more detailed assessment.
How Does Capsule Endoscopy Help Doctors See the Small Intestine?
One of the most commonly used tools for examining the small intestine is capsule endoscopy.
For many patients, the idea of swallowing a camera sounds unusual at first. However, capsule endoscopy offers a way to visualise areas that would otherwise be difficult to access.
During the procedure:
- A patient swallows a capsule containing a miniature camera
- The capsule travels naturally through the digestive tract
- Thousands of images are captured and transmitted to a recording device
- The capsule passes naturally through the body
Because the camera travels through the entire small intestine, doctors can review images of areas that cannot typically be reached with standard endoscopy.
What Is Balloon-Assisted Enteroscopy?
While capsule endoscopy is useful for identifying abnormalities, there are situations where doctors may need to examine an area more closely or obtain tissue samples.
In these cases, balloon-assisted enteroscopy may be considered.
This specialised procedure uses:
- A flexible endoscope
- Small balloons that help advance the scope through the small intestine
Unlike capsule endoscopy, balloon-assisted enteroscopy may allow doctors to:
- Take biopsies
- Remove certain lesions or polyps
- Treat some sources of bleeding
The choice between investigations depends on the patient’s symptoms and previous test results.
Can Imaging Scans Also Be Used to Examine the Small Intestine?
Not all small bowel investigations involve endoscopy.
In some situations, imaging studies may provide additional information about the digestive tract and surrounding structures.
Examples include:
- CT enterography
- MRI enterography
These scans may help identify:
- Inflammation
- Narrowed areas of the intestine
- Tumours or masses
- Complications related to inflammatory bowel disease
Doctors may use imaging alongside endoscopic procedures to gain a more complete understanding of the condition.
What Conditions Can Be Found in the Small Intestine?
The small intestine can be affected by a variety of conditions, many of which may not cause obvious symptoms initially.
Investigations may help identify:
- Crohn’s disease
- Small bowel ulcers
- Sources of gastrointestinal bleeding
- Polyps
- Benign or malignant growths
- Areas of inflammation
- Vascular abnormalities
Identifying the source of symptoms can help guide treatment and ongoing management.
When Should You See a Gastroenterologist About Unexplained Digestive Symptoms?
It can be frustrating to continue experiencing symptoms when previous tests have not provided clear answers. However, persistent symptoms should not be ignored simply because initial investigations were normal.
You may consider consulting a gastroenterologist if you have:
- Ongoing abdominal discomfort
- Iron deficiency anaemia
- Unexplained gastrointestinal bleeding
- Chronic diarrhoea
- Unexplained weight loss
- Persistent digestive symptoms despite previous investigations
A consultation can help determine whether specialised tests of the small intestine may be appropriate.
Frequently Asked Questions
1. Why can't a regular endoscopy see the entire small intestine?
A standard gastroscopy only reaches the upper portion of the small intestine, while a colonoscopy examines the lower digestive tract. Much of the small intestine lies beyond the reach of these procedures.
2. Is capsule endoscopy painful?
No. Capsule endoscopy is generally painless and involves swallowing a small camera capsule that passes naturally through the digestive tract.
3. What happens if capsule endoscopy finds an abnormality?
Depending on the findings, additional investigations such as balloon-assisted enteroscopy, imaging studies, or biopsies may be recommended.
4. Can capsule endoscopy replace colonoscopy?
No. Capsule endoscopy and colonoscopy examine different parts of the digestive tract and are used for different purposes.
5. How do doctors decide which small bowel test is needed?
The choice depends on symptoms, medical history, previous investigations, and the suspected condition.
Book a Consultation for Hidden Digestive Conditions
Early Detection Matters, Book a Consultation
When symptoms persist, but routine investigations do not provide clear answers, the small intestine may require further evaluation.
Advances such as capsule endoscopy and balloon-assisted enteroscopy allow doctors to examine areas of the digestive tract that were once difficult to access, helping to investigate unexplained bleeding, anaemia, abdominal pain, and other digestive concerns.
Dr Lin Cui Li, a gastroenterologist at Mount Elizabeth Medical Centre, provides evaluation for digestive symptoms and conditions affecting the oesophagus, stomach, intestines, liver, biliary system, and pancreas.
GastroClinic is located at:
3 Mount Elizabeth, #06-10 Mount Elizabeth Medical Centre, Singapore.
If you have ongoing digestive symptoms despite previous investigations, book a consultation to discuss whether further evaluation of the small intestine may be appropriate.
