FREE LECTURE NOTES ON GASTRIC FUNCTION TESTS
Dr Vijay Marakala, MBBS. M.D.
Department of Biochemistry,
International Medical School,
Analysis of Resting contents
Fractional Test Meal Analysis
Analysis after Stimulation
Tubeless Gastric Analysis
Please refer following textbook
Textbook of Medical
By M. N. Chatterjea, Rana
Chemical examination of gastric contents
has limited but specific value in diagnosis &
assessment of disorders of upper GIT.
Normal fasting gastric juice per day is about
1L. Stomach of a person taking a normal diet
secretes 2L 3L of gastric juice per day.
Contents of stomach should be examined
During resting period
During digestion after meals
Chief constituents of Gastric juice are:HCl
walls act as
To diagnose Gastric Ulcers
To exclude the diagnosis of Pernicious
anaemia & Peptic ulcer
For presumptive diagnosis of Zollinger
To determine the completeness of
Gastric contents are collected using Ryle’s tube
1. Examination of Resting contents(Gastric Residuum)
2. Fractional Test Meal Analysis
3. Analysis after Stimulation
a. Alcohol stimulation
b. Caffeine stimulation
c. Histamine stimulation
d. Augmented Histamine test
e. Insulin stimulation
f. Pentagastrin test
4. Tubeless Gastric Analysis
EXAMINATION OF RESTING CONTENTS:
Contents of the stomach collected after overnight fasting. Some of the important
physical and chemical characteristics are:
Consistency - Fluid
Colour – clearDark red or brown*
colourless or slightly Due to blood
yellowish or green
Bile – occasionally
Mucus - small
Lactic acid , butyric
acid present in large
• Hypersecretion of Gastric juice
• Retention due to delayed
• Regurgitation of duodenal
• Carcinoma of stomach
• Bleeding Gastric ulcer
• Carcinoma of stomach
• Intestinal Obstruction and ileal
• Gastritis and carcinoma of
• Hypochlorhydria, achlorhydria and
Free aciditymeasures only HCl.
Total acidity – includes HCl and other organic acids. Normal 10-40mEq/L
• Atrophic gastritis, Ca stomach
• Zollinger-Ellison syndrome
FRACTIONAL TEST MEAL ANALYSIS:
Introduction of Ryle’s tube in stomach of fasting patient and removal of residual
gastric contents and its analysis. Then ingestion of ‘TEST MEAL’ and removal of
gastric contents after meal.
There are different types of test meals have been used
Ewald test meal (2 pieces toast+250 ml tea)
Free acid rises steadily from 15 min – ½ hr/45 min
Hyperchlorhydria: When free acid is > 50mEq / L. Seen in duodenal ulcer,
gastric ulcer, gastric carcinoma.
Seen in carcinoma of stomach, atonic dyspepsia
Achlorhydria: No HCl but pepsin is present. Seen in Ca stomach, chronic
Achylia gastrica: Both HCl and pepsin are absent. Seen in later stage of Ca
stomach chronic gastritis and pernicious anaemia.
ANALYSIS AFTER STIMULATION:
ALCOHOL STIMULATION TEST:
The residual contents removed after overnight fasting
100ml of 7% ethyl alcohol is given
Samples are taken every 15 min
Analysed for free, total acidity, pepsin, blood, bile and mucus.
CAFFEINE STIMULATION TEST:
Stimulus is caffeine sodium benzoate -500 mg in 200 ml water given orally.
Samples are taken every 15 min then analysed for free, total acidity, pepsin,
blood, bile and mucus.
HISTAMINE STIMULATION TEST:
Histamine is the powerful stimulant for HCl in normal stomach
Acts on receptors of oxyntic cells
Done to differentiate between “true” achlorhydria from “false”
There are two types of Histamine stimulation test:
Standard Histamine test
Augmented Histamine test
Standard Histamine test:
Histamine is given subcutaneously 0.01mg/kg body weight
Absence of HC indicates “Achylia gastrica (true achlorhydria)
Increase in HCl indicates Duodenal Ulcer
Augmented Histamine test (Kay’s test):
It is more powerful test than standard Histamine test as it provides more reliable
proof of an inability to secrete acid.
Procedure: After overnight fast, residual contents are analysed and
contents are collected every 20 min for an hr.
Halfway through this period 4ml of mepyramine maleate (anthisan), given
IM, to block H1 receptors.
At the end of hr histamine acid phosphate, 0.04mg / kg bwt, SC given and
contents removed every 15 min for 1 hr.
Normal response: Upto 10 mEq/hr acid is present in pre histamine specimens
with 10 -25 mEq/hr in post histamine specimens.
In pernicious anaemia: No free HCl secreted
In duodenal ulcer: Higher values are obtained sometimes even > 100 mEq/hr
INSULIN STIMULATION TEST (HOLLANDER’S TEST)
Hypoglycemia produced by administration of Insulin is potent stimulus for gastric
Indication: To check the effectiveness of vagotomy in patients with
Stimulus – 15 unit of soluble insulin iv
I. Before operation
After successful vagotomy, there is no
response and acid level is very low.
It is a potent stimulator, causing max stimulation after assessing basal secretion
rate; hence it is a measure of Total Parietal Mass.
• Procedure: after removing the residual contents, the gastric juice secreted
for next 1 hr is collected as a single sample, which is called BASAL
SECRETION. Then injection of Pentagastrin is given at a dose of 6
microgram/kg bwt, subcutaneously. Collect 4 specimens at 15min intervals
for next 1 hour and analysed.
• Basal secretion
• After pentagastrin
stimulus, it is 2040mEq/hr
• Mean 43
• >40 indicates
In Duodenal ulcer
• Basal secretion is
> 10 mEq / hr
in ZollingerEllison syndrome
TUBLESS GASTRIC ANALYSIS
Swallowing a Ryle’s tube is an unpleasant procedure so tubeless gastric
analysis avoids discomfort of naso-gastric tube.
• Fasting secretion is stimulated by histalogue, after 1 hr dye bound resin
“Diagnex Blue” with “Azure A” is given orally.
• In the presence of HCl resin releases dye, which is absorbed & later
excreted in urine
• The quantity of dye in urine provides indication of presence /absence of
• It is not reliable in patients with renal diseases, urinary retention,
malabsorption, pyloric obstruction etc.
• Used only as a screening test