NCLEX Review: Gastrointestinal Diagnostic Procedures

There are numerous tests that may be used to evaluate the GI system. In this NCLEX review video, we will take a look at lab tests, imaging tests, and endoscopic procedures. We will explore the purpose of the tests, the preparation required, the nurse’s responsibility to the patient, and the aftercare instructions.

Lab Tests

  • Blood tests
    • Stomach – gastrin test
    • Pancreas – amylase, lipase, calcium
    • Biliary system – total bilirubin, alkaline phosphatase
    • Intestines – total protein, D-Xylose absorption test, lactose intolerance test
  • Urine tests – evaluates GI function
    • Urine bilirubin
    • Urobilinogen
    • Urine amylase
  • Stool tests
    • Stool culture
    • Fecal occult blood test


Imaging tests

  • Barium swallow (upper GI series) – view esophagus, stomach, & duodenum by x-ray or fluoroscopy
  • Barium enema (lower GI series) – view lower part of small intestine, large intestine, & rectum by x-ray
  • Ultrasound – view abdominal organs with high-frequency sound waves
  • Computed Tomography (CT) – two-dimensional x-ray images showing details of bones, muscles, fat, & organs – used to assess gallbladder, biliary ductal system, or pancreatic problems
    • CT angiography – combines CT scan with injection of contrast media, to emphasize differences in tissue density
  • Magnetic resonance imaging (MRI) – uses strong magnetic fields, radio frequencies, & computer to see detailed images of organs, soft tissues, bone & all other structures in body
  • GI nuclear scanning – radioactive material introduced into body & special camera shows GI tract better than standard x-ray
    • 5 types – GI bleeding scan, liver-spleen scan, gallbladder nuclear scan, gastroesophageal reflux scan, gastric emptying scan
  • Cholangiography – x-ray with contrast to identify stones, strictures, or tumors of bile ducts


Endoscopy procedures – visualizing the inside of GI tract with a fiberoptic scope

  • Upper GI endoscopy – look at esophagus, stomach, or duodenum
    • EGD (esophago-gastro-duodenoscopy) – looks at the whole region
  • Endoscopic retrograde cholangio-pancreatography (ERCP) – identifies stones, tumors, or narrowing in biliary & pancreatic ducts
  • Magnetic resonance cholangio-pancreatography (MRCP) – uses MRI to look at gallbladder, biliary ducts & pancreatic duct
  • Colonoscopy – examines the entire colon
  • Sigmoidoscopy – examines the anus, rectu, and distal sigmoid colon
  • Capsule endoscopy – visualize small intestine with a swallowed capsule containing a light & camera
  • Virtual colonoscopy (really an imaging test) – uses CT scan to create a 3-D pictures of inside of colon


Other diagnostic tests

  • Esophageal function tests
    • Manometry – measures pressure changes in esophagus
    • Esophageal pH monitoring – tests for acid reflux in esophagus over 24 hrs
    • Acid clearing test – tests esophageal motility using HCl
    • Bernstein test (acid perfusion test) – tests for pain/heartburn, using HCl
  • Gastric function tests
    • Gastric analysis

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by Mometrix Test Preparation | Last Updated: January 14, 2021