Gastrointestinal (GI) function tests are important diagnostic tools that help assess how well the digestive system is working. There are many different types of GI function tests, but two of the most common and useful are:
1. Upper Endoscopy
An upper endoscopy, also known as an EGD (esophagogastroduodenoscopy), is a procedure that allows doctors to directly see the upper part of the digestive tract. This includes the esophagus, stomach, and first part of the small intestine called the duodenum.
During an upper endoscopy, a thin, flexible tube with a light and camera at the tip called an endoscope is inserted through the mouth and down the throat. This allows the doctor to get a close look at the lining of these areas.
Upper endoscopy is most commonly used to:
- Evaluate symptoms like difficulty swallowing, abdominal pain, reflux, or GI bleeding
- Screen for certain cancers, like esophageal or stomach cancer
- Diagnose diseases like celiac disease, gastritis, ulcers, or inflammation
- Perform certain treatments, like stretching narrowed areas or removing polyps
The procedure usually takes about 5-10 minutes and is done either in a hospital or outpatient clinic. Medication to relax the patient is generally given intravenously before the test. The endoscope does not interfere with breathing during the exam.
Advantages of Upper Endoscopy
- Direct visualization of the upper GI tract
- Ability to take biopsies of abnormal tissue
- Can perform additional interventions (treatments) during the same procedure
- Minimally invasive
- Usually done as an outpatient procedure
Disadvantages of Upper Endoscopy
- Sedation required, so someone will need to drive the patient home after
- Small risk of bleeding or tear in GI tract wall
- May miss certain small problems
- Does not give information about the lower GI tract
2. Colonoscopy
A colonoscopy is a procedure that allows examination of the entire length of the colon and the very end of the small intestine. It is considered the gold standard test for colon cancer screening and diagnosis.
During a colonoscopy, the doctor inserts a colonoscope (long, flexible tube with a camera at the tip) into the anus and guides it throughout the entire large intestine. This allows the lining to be inspected closely for any abnormalities.
The main uses of colonoscopy include:
- Cancer screening for colorectal cancer beginning at age 45
- Evaluating gastrointestinal symptoms like bleeding, changes in bowel movements, or abdominal pain
- Monitoring patients with a history of polyps or colon cancer
- Evaluation of inflammatory bowel diseases like Crohn’s disease or ulcerative colitis
The procedure typically takes 20-30 minutes. Sedation is used to keep patients comfortable. During the test, the doctor can take biopsies of tissue and remove polyps or abnormal growths.
Advantages of Colonoscopy
- Only method that visualizes the entire colon
- Can obtain tissue samples and remove polyps/tumors
- Generally safe and well-tolerated with sedation
- Recommended screening test for colorectal cancer beginning at age 45
Disadvantages of Colonoscopy
- Requires thorough colon cleansing preparation the day before
- May miss very small polyps
- Sedation required so someone must drive the patient home
- Small risk of bleeding or tear in the colon wall
Key Differences Between Upper Endoscopy and Colonoscopy
| Upper Endoscopy | Colonoscopy |
|---|---|
| Looks at upper GI tract including esophagus, stomach, and duodenum | Looks at the entire colon and end of small intestine |
| Does not require prior bowel preparation | Requires thorough colon cleansing the day before |
| Performed for evaluation of upper GI symptoms like dysphagia, reflux, or abdominal pain | Performed for colorectal cancer screening, lower GI bleeding, changes in bowel habits |
| Takes about 5-10 minutes | Takes about 20-30 minutes |
| Lower risk of complications like bleeding | Slightly higher risk of complications like bleeding due to instrumentation of entire colon |
When are these tests recommended?
There are guidelines on when these tests should be performed for screening and diagnosis:
Upper Endoscopy Recommendations
- For chronic GERD symptoms that persist despite medication treatment
- Dysphagia or odynophagia – difficulty or pain with swallowing
- Persistent nausea/vomiting of unknown cause
- Upper abdominal pain with or without GI bleeding
- Screening for certain cancers like gastric cancer in high risk populations
- Anemia or GI bleeding of unknown origin
- Abnormal imaging findings suggesting disease
- Monitoring of acid reflux, ulcers, enlarged veins in the esophagus
Colonoscopy Recommendations
- Colorectal cancer screening, beginning at age 45
- Lower GI bleeding
- Iron deficiency anemia when upper endoscopy does not reveal a cause
- Chronic diarrhea or constipation of unknown cause
- Surveillance of inflammatory bowel disease
- For follow up of previously detected polyps or colorectal cancer
- Abnormal imaging findings suggesting colon disease
- Family history of colorectal cancer or polyps
Both upper endoscopy and colonoscopy play important roles in evaluating GI problems. They allow direct visualization and tissue sampling of the upper and lower GI tract. Following appropriate screening guidelines and discussing concerns with a doctor can ensure these tests are used in the most effective manner.
How to Prepare for Upper Endoscopy and Colonoscopy
Proper preparation helps ensure upper endoscopy and colonoscopy procedures go smoothly and give the best results. Here is how to prepare:
Upper Endoscopy Preparation
- Fast after midnight the night before, including no food, liquids, gum, or candy
- Discuss medications with your doctor, especially blood thinners or diabetes medications
- Arrange for a ride home since sedation will be given
- Wear comfortable loose fitting clothing
Colonoscopy Preparation
- Follow a clear liquid diet only starting 1-2 days before
- Take a bowel prep solution as instructed to thoroughly cleanse the colon
- Avoid foods with nuts or seeds which can clog the scope
- Make arrangements for a ride home following sedation
- Make sure to follow all preparation instructions provided by your doctor
Doing the required preparation helps the doctor adequately see the lining of the GI tract during the procedure. It also reduces risks of complications. Be sure to ask your doctor if you have any questions about preparing for your upper endoscopy or colonoscopy.
Understanding Your Results
After an upper endoscopy or colonoscopy, the doctor will explain the results. This includes any findings they observed as well as results from any biopsies taken. Some key things to understand about your results include:
Visual Findings
The doctor will describe any abnormalities seen during the visual examination of your upper or lower GI tract. This may include inflammation, ulcers, polyps, strictures, or masses. Pictures and diagrams are often used to show findings.
Biopsy Results
If biopsies were taken, the results will indicate if any abnormal tissue was found. Certain patterns of cell changes may indicate specific conditions like celiac disease, cancer, or inflammatory bowel disease, for example.
Recommendations
Based on the test results, the doctor will make recommendations about any needed treatment or follow up. This may include medications, dietary changes, surgery, repeat testing, or specialist referrals. Make sure you understand the next steps in your care.
Questions to Ask
Don’t hesitate to ask your doctor any questions about your test results, including:
- What is the exact diagnosis based on my results?
- Do I need any additional tests or to see a specialist?
- What treatment options are recommended?
- What symptoms should prompt me to call the doctor?
- How often will I need follow-up examinations?
Getting clear information about your test results allows you to get the care and treatment you need after an upper endoscopy or colonoscopy.
Conclusion
Upper endoscopy and colonoscopy are common, safe, and effective procedures used to evaluate digestive system problems. By understanding how to prepare, what to expect during the tests, and what the results mean, you can make the most of these valuable screening and diagnostic tools for optimal gastrointestinal health.