1. Overview: Evaluation of the Gastrointestinal Tract

2. Diagnostic Tests Radiology Imaging Endoscopy Plain radiology
The purpose of reviewing these tests is so that you will have an understanding of the procedures your patients are going through.
The tests are broken down into 3 main categories.
Radiology
Plain radiology
Upper GI series
Lower GI series
Imaging
Ultrasonography (US)
Computed tomography (CT)
Magnetic resonance imaging (MRI)
Endoscopy
Esophagogastro- duodenoscopy (EGD)
Colonoscopy
Sigmoidoscopy
Endoscopic retrograde cholangiopancreato- graphy (ERCP)

3. Plain Radiology Abdominal x-ray Often used to evaluate abdominal pain
A plain abdominal x-ray is often called a KUB, which stands for the kidney, ureters, and bladder. This shows a normal abdominal x-ray. Organs that you can see are the kidney and spleen. Also, note that bowel gas shows up as dark, black, spaces.
Abdominal x-ray
Kidney, ureters, and bladder (KUB)
Other: esophagus, stomach, intestine
Often used to evaluate abdominal pain

4. Upper Gastrointestinal Series
For UGI series, patients are not allowed to eat or drink 8-12 hours prior to the study. Barium is then swallowed by the patient prior to the study. The barium shows up very well on xray. The flow of barium through the esophagus, stomach, duodenum, and small bowel can also be observed.
Barium is not recommended if there is colonic obstruction because the barium can turn into a solid, which can worsen an obstruction. Barium should not be used if CT scan is planned. The barium stays in the colon and is too radio-dense for the CT scanner. Patients need to drink lots of fluid after barium to flush it out.
Focus on esophagus, stomach, and small intestine
Often called ‘barium swallow’
“Small bowel follow- through”
Includes small intestine
Evaluates obstruction, tumors, ulcers, cancer, PUD, GERD

5. Upper Gastrointestinal Series
This is a barium swallow that shows a gastric ulcer because the barium is is shown by the ‘outpouching’.
Gastric Ulcer

6. Lower Gastrointestinal Series
For lower GI series, bowel cleansing agents are given to the patient the night before the procedure – examples are: bisacodyl, magnesium citrate, magnesium hydroxide, and polyethylene glycol.
Barium used to contrast large intestine and rectum
Evaluates obstruction, lesions, Crohn’s disease, ulcerative colitis, cancers, diverticulitis

7. Lower Gastrointestinal Series
Examples of lower GI series with barium.

8. Ultrasonography (US) Provide images of deeper structures
Ultrasound of the pancreas.
Provide images of deeper structures
Pancreas
Gallbladder
Limited by the presence of gas or obesity

9. Ultrasonography (US)
Ultrasound of the gallbladder and liver.

10. Computed Tomography (CT) Scan or Computed Axial Tomography (CAT) scan
CT scans provide much more detailed information. Good for detecting masses, such as, liver CA, pancreatic CA, intra-abdominal abscess, and cysts.
Transverse planes of tissue by radiography
Not limited by the presence of gas or obesity

11. Computed Tomography (CT) Scan or Computed Axial Tomography (CAT) scan
Examples of CT scan – note lung and liver on the left.
Liver, gallbladder, kidney, pancreas, stomach, and spleen on the right.

12. Computed Tomography (CT) Scan or Computed Axial Tomography (CAT) scan
Moving further down – can see the colon, both kidneys and on the right, the ascending and descending colon.

13. Magnetic Resonance Imaging (MRI)
Similar to CT scan, but more sensitive. Advantages include the absence of radiation, ability to present sectional images in any place, and improved soft tissue differentiation.
High-strength magnetic field creates radiofrequency irradiation that ‘excites’ cells
Greater sensitivity to identify liver tumors

14. Endoscopy Illuminated optical instrument Medications used
Endoscopy is most helpful for assessment of the mucosa in gastritis and identifying a specific bleeding site. It is also often used to evaluate GERD, PUD, cancer, UGI bleeding, feeding tube placement, and dysphagia.
The endoscope has many other devices attached, such as, biopsy forceps, brushes, electrocautery proves, injecting devices, wash tubes, and snares. Fluid can also be taken from hollow organs and air can be passed to improve visualization. A video on the tip images on to a TV screen.
Topical anesthesia with a gargle or spray of viscous lidocaine or benzocaine is used to help the patient help swallow the device. Also, midazolam is used for light sedation and as an anxiolytic due to retrograde amnesia and for rapid reversal in overdose situations. Opioids can be used if the patients experiences severe pain.
Patients NPO for 6-8 hours.
Illuminated optical instrument
Biopsy forceps
Cytology brushes
Electrocautery probes
Medications used
Topical anesthetic
‘Conscious sedation’
Contraindicated in severe respiratory or cardiac failure, perforation

15. EGD - Esophagogastroduodenoscopy
Normal esophagus with white to tan smooth mucosa.
Normal Esophagus

16. EGD - Esophagogastroduodenoscopy
Esophagogastric Junction
Normal esophagus is white to tan smooth mucosa
Transition from white squamous mucosa to pink columnar mucosa

17. EGD - Esophagogastroduodenoscopy
Normal Stomach

18. EGD - Esophagogastroduodenoscopy
Normal Pyloric Junction

19. Reflux Esophagitis
These patients has signs of erosive esophagitis due to GERD. They may or may not be experiencing symptoms of GERD. Symptoms highly specific for GERD are heartburn, regurgitation, or both, which often occur after meals (esp. large or fatty). Often aggravated by recumbency or bending and relieved by antacids.
Esophagitis may progress to scarring and stricture formation. Occurs in up to 50% of patients with GERD. Also, Barrett’s esophagus can develop over the long-term.
The pathogenesis of GERD in most affected pts is inappropriate relaxation of the lower esophageal spincter (LES).

20. Barrett’s Esophagus
GERD is an important factor in the development of Barrett’s, where the normal squamous epithelium is replaced with columnar epithelium of the stomach. Once Barrett’s esophagus develops, it is not likely that it will regress
with either medical or surgical therapy.
Replacement of squamous mucosa with columnar epithelium

21. Esophageal Varices
Spurting esophageal varix in a 78 year-old man with portal hypertension caused by colon cancer metastatic to liver. The bleeding caused the varix to decompress and flatten. View on the right shows the jet of blood ricocheting off the opposite esophageal wall.

22. Gastric Ulcers
Shallow and sharp demarcation.

23. NSAID-induced Gastritis
About 20 million people in the US take NSAIDs, risk for hospitalization for serious GI event is 1-2%, approx 200K-400K hospitalizations/year.
Patients with RA or OA taking NSAIDs have an ulcer incidence of 15-20%. The overall risk for serious adverse GI events in patients taking NSAIDs is 3 times greater than those to don’t. Risk increases 5 times if >60 YOA. Only 1 in 10 NSAID-induced ulcer bleeds.
Risk factors: prior history of GI event, >60 YOA, high dosage, concurrent use of corticosteroids, concurrent use of anticoagulants.
From Am J Gastroenterology 1998;93(11): A guideline for the treatment and prevention of NSAID-induced ulcers.

24. Helicobacter pylori
Short, curved rod-like organisms overlying the mucosa. With gram stain, they are gram-negative. H. pylori produce urease, protease, and phospholipases that break down mucosal glycoproteins and damage epithelial cells, leading to inflammation - a chronic gastritis, that is usually asymptomatic. Duodenal ulcers, gastric ulcer, and antral gastirits are associated with H. pylori infection. Incidence of H. pylori increases with age, with 1/2 of American adults infected by age 50.

25. Helicobacter pylori CLO test ‘Campylobacter Like Organism’ test
Test for H. pylori in patients with active ulcers, history of ulcers, or gastric mucosa-associated lymphoid tissue lymphomas. Medication regimen must contain 2 antibiotics for days. PPI or H2 antagonist necessary for ulcer healing. Can use urea breath test after Rx to confirm eradication.
From Arch Intern Med 2000;160(9): H. pylori related disease: guidelines for testing and treatment.
CLO test
‘Campylobacter Like Organism’ test
Campylobacter means “curved bacteria”
Helicobacter means “spiral or helical bacteria”
Urease enzyme of H. pylori causes medium to change to red
Top - negative or unused test
Middle - red around a biopsy infected with H. pylori
Bottom - final result of biopsy infected with H. pylori

26. Colonoscopy Normal Cecum
Colonoscopy and ERCP are more complex than EGD.
Patients prepared for colonoscopy with laxatives and tap water enemas or by total-gut lavage. NPO for 8 hours.
Used to see polyps, follow-up abnormal finding on barium enema, narrowing (from ischemia, diverticular disease, etc.), chronic bleeding, inflammatory bowel disease (differentiate Crohn’s from ulcerative colitis)
Normal Cecum

27. Colonoscopy
Normal Ascending Colon

28. Colonoscopy
Normal Transverse Colon

29. Colonoscopy
Normal Sigmoid Colon

30. Colonoscopy
Normal Rectum

31. Clostridium difficile
A common cause of antibiotic induced diarrhea results from overgrowth of c. difficile. Causes profuse, watery, foul-smelling, and often green diarrhea. The bacteria can appear as light-raised lesions and colon often has a brown, yellowish, tan mucosa.

32. Nifedipine (Procardia XL®)

33. Sigmoidoscopy
NPO 8-12 hours.

34. Endoscopic retrograde cholangiopancreatography (ERCP)
ERCP places a side-viewing instrument in the descending duodenum. The papilla of Vater is cannulated, X-ray contrast medium is injected, and the pancreatic ducts and hepatobiliary tree are visualized radiographically. ERCP is performed on an c-ray table after sedation of the patients.

35. Endoscopic retrograde cholangiopancreatography (ERCP)
This ERCP shows obstruction in the hepatobiliary tree. Stents can be placed at this time to open up the biliary tree.

36. Esophageal Manometry Evaluates esophageal motor functions
Used to further evaluate GERD if symptoms do not resolve with therapy.
Evaluates esophageal motor functions
Lower esophageal sphincter
Delayed gastric emptying
Measures esophageal pressure and peristalsis
Quantifies esophageal competence and body motor activity

37. Ambulatory pH Monitoring
Ambulatory pH testing helps to confirm GERD in pts with symptoms without evidence of mucosal damage and to monitor the esophageal acid exposure of pts with refractory symptoms. Usually used only in research studies because the test is more invasive than a trial of pharmacologic therapy.
Best method to determine the actual amount of reflux
Links esophageal acid exposure with patient symptoms
pH probe placed above the distal esophagus

38. Summary