Diagnostic tests for GI disorders- include physical evaluation, blood tests, imaging techniques. Learn the methods of diagnosis in detail, for gastrointestinal disorders.

1. DIAGNOSTIC TESTS FOR
GASTROINTESTINAL
DISORDERS

2. CONTENTS
⮚Physical Evaluation
⮚Lab Tests
⮚Endoscopic procedures
⮚Imaging Tests

3. Physical Evaluation
• Observation: - Fever, Dehydration, Skin rashes.
• Examination of Nutritional Status – Signs of Weight Loss.
• Examination of Hands – Clubbing of fingers(sign of heart or lung disease),
Koilonychia (spoon nails, a sign of anaemia), etc.
• Examination of Mouth, Head and Neck – Mouth ulcers, Dentition,
Lymphadenopathy, Angular stomatitis, Glossitis, etc.
• Abdominal Examination – Distention, Respiratory movements, Scars, Lesions,
Colour, Bowel sounds, Ascites, etc.
• Examination of Groin – Hernias, Lymph nodes.
• Rectal Examination – Fistulae, Haemorrhoids, Masses, etc.

4. Lab Tests
- Lab tests may include a number of tests like – Blood tests, Breath tests, Faecal occult blood
test, Stool culture, etc. depending on the suspicion of the physician.
A. Blood Tests
- In laboratory analysis of blood, specific blood factors are looked at.
- The time for the results to come vary from test to test.
Examples:
- Celiac disease – blood test results will show higher than normal levels of certain antibodies
against a protein called gluten, which are found in wheat, barley, and other grains.
- Inflammatory bowel disease – blood test will show an increased white blood cell count, which
may indicate inflammation.
- Allergies – presence of IgE antibodies, which are made when a food is misidentified as a threat
by the immune system.
- Ulcers (H. pylori infection) – blood test can reveal if a person has a Helicobacter Pylori infection,
which is an indicator of stomach ulcers and could put a person at greater risk of stomach cancer
– which is determined by looking for anemia — a low amount of white blood cells — which can
be found by a complete blood count (CBC) test.

5. - In certain cases, antigens may be detected in blood upon infection by a virus or
bacteria.
- Example of such a case is Hepatitis:
Hepatitis Marker detected in blood test
Hepatitis A Blood test determines IgM antibody to the
hepatitis A virus.
Hepatitis B Blood test determines HBsAg, HBcAb,
HBeAg, IgM anti-HBc, Hepatitis B DNA.
Hepatitis C Blood test determines antibodies to HCV,
Hepatitis C RNA.
Hepatitis D Blood test determines antibodies to HDV.
Hepatitis E Blood test determines antibodies to HEV.

6. B. Breath Tests
- Hydrogen breath test – Hydrogen breath tests are widely
used to explore pathophysiology of functional
gastrointestinal (GI) disorders.
- Small intestinal bacterial overgrowth (SIBO) and
carbohydrate malabsorption are disorders detected by
these tests that have been proposed to be of great
importance for symptoms of GI diseases.
- Glucose hydrogen breath test is more acceptable for
diagnosis of SIBO.
- Lactose and fructose hydrogen breath tests are used for
detection of lactose and fructose maldigestion respectively.

7. C. Faecal occult blood test
- A fecal occult blood test checks for hidden (occult) blood in
the stool.
- It involves placing a very small amount of stool on a special
card.
- The stool sample is collected and sent to a lab for testing.
- Blood in the stool may be a sign of colorectal cancer or other
problems, such as ulcers or polyps.

8. D. Stool culture
- A stool culture checks for the presence of abnormal bacteria in the
digestive tract that may cause diarrhea and other problems.
- The test helps in diagnosing medical conditions, such as
inflammatory bowel disease, gastric or colon cancer, anal fissures,
H. pylori infection, haemorrhoids, as well as to detect the presence
of blood in your stool sample.
- A small sample of stool is collected and sent to the lab.
- Results come in 2-3 days and the test will show whether abnormal
bacteria are present or not.
Fig: Stool Culture

9. Endoscopic procedures
- Endoscopy is a procedure that allows a doctor to view the inside of a person's body.
- Doctors use it to diagnose diseases in the following parts of the body : Esophagus,
Stomach, Colon, Ears, Nose, Throat, Heart, Urinary tract, Joints, Abdomen.
- During an endoscopy, the doctor inserts a tool called an endoscope into a person’s body.
Most endoscopes are thin tubes with a powerful light and tiny camera at the end.
- The endoscope's length and flexibility depend on the part of the body the doctor needs to
see.
- For example, a straight endoscope helps a doctor look at joints, whereas a flexible one
helps a doctor view the inside of the colon.

10. Types of Endoscopic procedures:
1. Colonoscopy
- Used to view the whole length of the large intestine (colon).
- It can help to find abnormal growths, inflamed tissue, ulcers, and
bleeding.
- A colonoscope is put into the rectum and moved up into the colon.
- A colonoscope is a long, flexible tube with a light on it that allows the
healthcare provider to see the lining of the colon and remove tissue
for further study (biopsy), if needed.
- A virtual colonoscopy is available that uses CT imaging to look at the
colon.
Fig: Colonoscopy

11. 2. Endoscopic retrograde cholangiopancreatography
(ERCP)
- Allows to diagnose and treat problems in the liver,
gallbladder, bile ducts, and pancreas.
- It combines X-ray and the use of an endoscope.
- The scope is guided through your mouth and throat and
then through the esophagus, stomach, and duodenum.
- The physician can look at the inside of these organs and
diagnose problems, if any.
- A tube is then passed through the scope and a dye
substance is injected that allows the internal organs to
appear on an X-ray.
Fig: Endoscopic retrograde cholangiopancreatography

12. 3. Esophagogastroduodenoscopy (EGD or upper
endoscopy)
- An EGD allows the physician to look inside the esophagus,
stomach, and duodenum with an endoscope.
- This scope is guided into the mouth and throat and then
into the esophagus, stomach, and duodenum.
- He or she can also insert instruments through the scope to
remove a sample of tissue for biopsy or for surgical removal
of a tissue mass.
- When an ultrasound probe is attached to a scope, an
internal ultrasound can be done – process known as
Endoscopic ultrasound (EUS).
Fig: Esophagogastroduodenoscopy

13. 4. Sigmoidoscopy
- A sigmoidoscopy is a diagnostic procedure that allows
the physician to examine the inside of a portion of the
large intestine, and is helpful in identifying the causes
of diarrhea, abdominal pain, constipation, abnormal
growths, and bleeding.
- A short, flexible, lighted tube, called a sigmoidoscope,
is inserted into the intestine through the rectum.
- The scope blows air into the intestine to inflate it and
make viewing the inside easier.
- A sigmoidoscopy is one type of test used to screen for
colon and rectal cancers.
Fig: Sigmoidoscopy

14. Imaging Tests
1. Barium beefsteak meal
- During this test, the patient eats a meal containing barium (a
metallic, chalky liquid used to coat the inside of organs so that they
will show up on an X-ray).
- This allows the radiologist to watch the stomach as it digests the
meal.
- The amount of time it takes for the barium meal to be digested and
leave the stomach gives the physician an idea of how well the
stomach is working and helps to find emptying problems that may
not show up on the liquid barium X-ray.
- Barium meal examination is usually performed to help diseases of
GIT like constrictions, hernias, obstructions or masses in the
esophagus or stomach, and inflammatory or other diseases of the
intestines.
- A barium swallow test may be done to diagnose problems in the
pharynx and esophagus, cancer of the head and neck, pharynx, or
esophagus, hiatal hernia, etc.
Fig: Barium beefsteak meal

15. 2. Colorectal transit study
- This test shows how well food moves through the colon.
- The patient swallows capsules containing small markers which are
visible on X-ray.
- The patient follows a high-fiber diet during the course of the test.
- The movement of the markers through the colon is monitored with
abdominal X-rays taken several times 3 to 7 days after the capsule is
swallowed.
- This test is most often used in patients who are suffering from
chronic constipation.
Fig: Colorectal transit study

16. 3. Computed Tomography scan (CT scan)
- It is an imaging test that uses X-rays and a computer to make
detailed images of the body.
- A CT scan shows details of the bones, muscles, fat, and organs.
- A computerized tomography (CT) scan combines a series of X-ray
images taken from different angles around your body and uses
computer processing to create cross-sectional images (slices) of the
bones, blood vessels and soft tissues inside your body.
- CT scan images provide more-detailed information than plain X-rays
do.
- A CT scan has many uses, but it's particularly well-suited to quickly
examine people who may have internal injuries from car accidents or
other types of trauma.
- It can be used to visualize nearly all parts of the body and is used to
diagnose disease or injury as well as to plan medical, surgical or
radiation treatment.
Fig: CT scan

17. 4. Defecography
- Defecography is an X-ray of the anorectal area that evaluates
completeness of stool elimination, identifies anorectal abnormalities,
and evaluates rectal muscle contractions and relaxation.
- During the exam, the patient's rectum is filled with a soft paste that is
the same consistency as stool.
- The patient then sits on a toilet positioned inside an X-ray machine, and
squeezes and relaxes the anus to expel the solution.
- The radiologist studies the X-rays to determine if anorectal problems
happened while the patient was emptying the paste from the rectum.
- The technique traditionally involves fluoroscopy and barium, but an
analogous MRI technique has also been developed MRI defecography).
- This test is used to evaluate disorders of the lower bowel that are not
diagnosed by tests such as colonoscopy or sigmoidoscopy.
Fig: Defecography

18. 5. Lower GI barium enema
- It is also called lower gastrointestinal series.
- A lower GI series is a test that examines the rectum, the
large intestine, and the lower part of the small intestine.
- Barium in the form of Barium sulfate is given into the
rectum as an enema.
- An X-ray of the abdomen shows strictures (narrowed
areas), obstructions (blockages), and other problems.
- A barium enema helps doctors find health conditions in the
colon and rectum, such as inflammation, polyps, and
cancer. Fig: Lower GI barium enema

19. 6. Magnetic resonance imaging (MRI)
- MRI is a diagnostic test that uses a combination of large magnets,
radiofrequencies, and a computer to produce detailed images of organs
and structures within the body.
- The patient lies on a bed that moves into the cylindrical MRI machine
where it takes a series of pictures of the inside of the body using a
magnetic field and radio waves and the computer enhances the pictures
produced.
- The test is painless, and does not involve exposure to radiation.
- Because the MRI machine is like a tunnel, some people are claustrophobic
or unable to hold still during the test to whom a sedative may be given to
help them relax.
- Metal objects cannot be present in the MRI room, so people with
pacemakers or metal clips or rods inside the body cannot have this test
done.
- It can be used to diagnose tumors of the abdomen or pelvis. diseases of
the liver, such as cirrhosis, and abnormalities of the bile ducts and
pancreas. inflammatory bowel disease such as Crohn's disease and
ulcerative colitis, etc.
Fig: MRI of abdomen
Fig: MRI machine

20. 7. Magnetic resonance
cholangiopancreatography (MRCP)
- The technique uses MRI to visualize the biliary and
pancreatic ducts non-invasively.
- The machine uses radio waves and magnets to scan
internal tissues and organs.
- This procedure can be used to determine whether
gallstones are lodged in any of the ducts surrounding
the gallbladder.
- Indications for the use of MRCP include – unsuccessful
or contraindicated ERCP, patient preference for non-
invasive imaging, patients considered to be at low risk
of having pancreatic or biliary disease and those with a
suspected neoplastic cause for pancreatic or biliary
obstruction
Fig: Magnetic resonance cholangiopancreatography

21. 8. Oropharyngeal motility (swallowing) study
- Also called a modified barium swallow test.
- This is a study in which the patient is given small
amounts of a liquid containing barium to drink with a
bottle, spoon, or cup.
- A series of X-rays is taken to evaluate what happens as
the liquid is swallowed.
- It could be used to diagnose diseases like dysphagia,
sphincter motility issues, etc.
Fig: Oropharyngeal motility study

22. 9. Radioisotope gastric-emptying scan
- During this test, the patient eats food containing a
radioisotope, which is a slightly radioactive substance that
will show up on a scan.
- The dosage of radiation from the radioisotope is very small
and not harmful, but allows the radiologist to see the food
in the stomach and how quickly it leaves the stomach, while
the patient lies under a machine.
- A Gastric Emptying Study is a test to determine the time is
takes a meal to move through a person's stomach (Gastric
emptying time).
- The technique is used to diagnose gastroparesis, a condition
in which the stomach's muscles don't work properly.
- Typically Tc-99m sulphur colloid or Tc-99m DTPA is the
radioisotope used.
Fig: Radioisotope gastric-emptying scan

23. 10. Ultrasound
- Ultrasound is a diagnostic imaging technique that uses high-frequency
sound waves and a computer to create images of blood vessels, tissues,
and organs.
- They are used to view internal organs as they function, and to assess
blood flow through various vessels.
- Gel is applied to the area of the body being studied, such as the
abdomen, and a wand called a transducer is placed on the skin.
- The transducer sends sound waves into the body that bounce off
organs and return to the ultrasound machine, producing an image on
the monitor.
- Intestinal ultrasound is a safe and inexpensive method that allows
visualization of the gastrointestinal tract and detection of
abnormalities.
- This examination involves the use of two different ultrasound
transducers: a low-frequency convex probe and high-frequency linear
probe.
Fig: Ultrasound

24. 11. Upper GI barium swallow
- It is also called upper gastrointestinal series.
- Upper GI series is a diagnostic test that examines the
organs of the upper part of the digestive system: the
esophagus, stomach, and duodenum.
- Barium is swallowed and X-rays are then taken to
evaluate the digestive organs.
- The technique is used for the diagnosis of upper GI
tract diseases like tumors, ulcers, hernias, diverticula
(pouches), strictures (narrowing), inflammation, and
swallowing difficulties.
Fig: Upper GI series in infants

25. REFERENCES
1. https://ukhealthcare.uky.edu/digestive-health-
program/diagnosis/blood-tests
2. https://www.hopkinsmedicine.org/health/treatment-
tests-and-therapies/digestive-diagnostic-procedures
3. https://www.urmc.rochester.edu/encyclopedia/conte
nt.aspx?ContentTypeID=85&ContentID=P00364
4. https://teslascans.com/stool-
test/#:~:text=A%20stool%20test%20is%20also,blood
%20in%20your%20stool%20sample.
5. https://www.cancer.net/navigating-cancer-
care/diagnosing-cancer/tests-and-procedures/types-
endoscopy
6. https://www.mayoclinic.org/tests-procedures/ct-
scan/about/pac-20393675
7. https://www.radiologyinfo.org/en/info/mri-abdomen-
pelvis