GASTROINTESTINAL FUNCTION TESTS
Indications:
Diagnosis of:
- Gastric-ulcer/ Peptic-ulcer
- Pernicious anaemia
- Zollinger Ellison Syndrome
- Completion of surgical vagotomy
Classification:
Examination
of
- resting juice content.
- fractional gastric juice.
- gastric juice after stimulation.
alcohol stimulation
caffeine
histamine
insulin/ pantagastrin
- Tubeless gastric analysis (Azure-A-resin)/ cation exchange resin - excreted into urine (H+ conc)
Sample
collection: Ryle’s Tube
ABNORMALITIES OF GASTRIC FUNCTION:
Increased Gastric HCl:
- Zollinger – Ellison Syndrome (a tumor of gastrin secreting cells of the pancreas)
- Chronic duodenal ulcer
- Excessive histamine production
Decreased Gastric HCl: Gastritis, gastric carcinoma, pernicious anaemia.
TESTS FOR
INTESTINAL FUNCTION:
Lactose
Tolerance Test –
- 50 gm lactose in 200 ml of water
- Blood specimen at Fasting, 30, 60 and 120 minutes.
- Normal : More than 30mg/dL.
- 20-30mg/dL borderline and <20mg/dL - lactase deficiency
D-Xylose
absorption test –
- 25 gm (0.5 gm/kg body weight in children) in 250ml water
- blood level after 30’, 1 hr and 2 hrs. (<25 mg/dL abnormal).
- urine for 5 hrs (normally 4 gm excretion) (> 20%)
- normal blood concentration with decreased urinary excretion ---> renal impairment/ incomplete urine collection
To differentiate pancreatic steatorrhoea and malabsorption steatorrhoea
Serum
carotenoids –
e.g.
lycopene, xanthophyll and carotene malabsorption
carotenoids (normal ranges 50 - 250mg/dL)
Fecal fat
analysis –
- normally 1 - 4gm/ 24 hrs (lipid free diet)
- < 7gm / (lipid rich diet)
- excretion in biliary obstruction
- exocrine pancreatic insufficiency
- diseases of small intestine
Qualitative
screening test –
- Sudan staining for fecal fat
- Normally 40 to 50 small neutral lipid droplets/ high power
Quantitative
fecal fat analysis –
- 72 hrs stool collection
- lipid rich diet for 2 days prior to test
- 50 – 100 gm of lipid each day
- reference range – 1 to 7gm/ 24 hrs
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