anatomy and physiology of gastro intestinal system

1. THE DIGESTIVE SYSTEM
PRESENTED BY:
HARSH RAMAN
M.Sc (N) 1st Year
Roll No-1914703

2. INTRODUCTION:
The digestive
system is the
collective name used
to describe the
alimentary canal,
some accessory
organs and a variety
of digestive process
that takes place at
different levels in
the canal to prepare
food eaten in the
diet for absorption.

3. THE DIGESTIVE SYSTEM
 The digestive tract is more than 10 meters (30
feet) long from one end to the other.
 It is continuous starting at the mouth, passing
through the pharynx, oesophagus (25 cm long) ,
the stomach, the small and large intestine and
ending in the rectum (12.5-15 cm long) & finally
into the anus.

4. HUMAN DIGESTIVE SYSTEM

5. FUNCTION OF THE DIGESTIVE
SYSTEM:
 INGESTION
 DIGESTION
 ABSORPTION
 ELIMINATION

6. INGESTION
It involves
 Placing the food into the mouth.
 Chewing the food into smaller pieces
(mastication).
 Moistening of the food with salivary secretion.
 Swallowing the food (deglutition).

7. DIGESTION
 During digestion, food is broken down into small
particles by the grinding action of the gastro-
intestinal tract (GIT) and then degraded by the
digestive enzyme into usable nutrients.

8. ABSORPTION
 During
absorption,
nutrients, water
and electrolytes
are transported
from the GIT to
the circulation.

9. ELIMINATION
 Food substances that
have been eaten but
cannot be digested and
absorbed are excreted
from the alimentary
canal as feces by the
process of defecation.

10. ORGANS OF DIGESTIVE SYSTEM
ALIMENTARY TRACT
 Mouth
 Pharynx
 Esophagus
 Stomach
 Small intestine
 Large intestine
 Rectum and anal
canal

11. ACCESSORY ORGANS OF DIGESTIVE
SYSTEM
 Three pairs of
salivary gland
 The pancreas
 The liver &
biliary tract.

12. STRUCTURE OF ALIMENTAY CANAL
The walls of the alimentary tract are formed by
4 layers of tissues.

13. 1) ADVENTITIA OR SEROSA
 This is the outer most layer and in the thorax it
consists of losse fibrous tissue and in the
abdomen the organs are covered by a serous
membrane (serose) called peritoneum.

14. PERITONEUM
 It is the largest
serous membrane of
the body. It has two
layers
 Parietal layer- which
lines the abdominal
valve
 Visceral layer- it
cover the organs
within the
abdominal and
pelvic cavities.

15. 2. MUSCLE LAYER
 It consist of two layer of
smooth (voluntary)muscle
 Contraction and relaxation of
these muscle layers occur in
waves, which push the
contents of the tract onwards.
 This type of contraction of
smooth muscle is called
“peristalsis”.
 Onward movement of the
content of the tract is
controlled at various points by
sphincters, which are
thickened rings of circular
muscle contraction of
sphincter regulates forward
movement and prevent the
backflow in the tract.

16. 3. Sub mucosa:
This layer consists of loose connective tissue,
blood vessels and lymphatics.

17. 4. MUCOSAL LAYER:
It consists of three layers of tissues.
 Mucus membrane
 Lamina propria
 Muscularis mucosa
o Mucus membrane:
It has three main function- protection, secretion,
and absorption.

18. MUCOSAL LAYER:
Lamina propria: it consisting of loose connective
tissue, which supports the blood vessels that
nourish the inner epithelial layer, and varying
amounts of lymphoid tissue that has a protective
function.
Muscularis mucosa: it is a thin outer layer of
smooth muscles that provides involutions of the
mucosa layer, gastric glands, and villi.

19. THE WALLS OF THE ALIMENTARY TRACT

20. MOUTH (ORAL CAVITY)
 The mouth or oral cavity is lined by mucous
membrane, consisting of stratified squamous
epithelium containing mucus secreting glands.

21. BOUNDARIES OF ORAL CAVITY
 Anteriorly : by lips
 Posteriorly : it is
continuous with
oropharynx
 Laterally: by muscles of
the cheeks
 Superiorly: by bony
hard palate & muscles of
soft palate
 Inferiorly: by soft tissue
of floor, mouth &
tongue.

22. TOUNGUE
 It is a voluntary muscular structure.
 It is attached by its base to the hyoid bone & by
frenulum to the floor of the mouth.
 Its superior surface consists of stratified squamous
epithelium, with little projection called as papillae,
containing taste buds.

23. FUNCTIONS OF TOUNGE
The term plays an important role in
 chewing ( mastication),
 swallowing( deglutition),
 speech &
 taste.

24. TEETH
The teeth are embedded in sockets of the mandible and maxilla.
Each person has two sets of teeth, the temporary &
permanent teeth.
 TEMPORARY (DECIDUOUS) - They are 20 in number,
10 in each jaw. They begin to erupt at the age of six months
& all are present by the age of 24 months.
Shapes- molars 2/2, premolars, canine 1/1, incisors 2/2.

25. TEETH
 PERMANENT TEETH- They are 32 in
number & begin to replace the temporary teeth
in the sixth year of age. It is usually completed
by the 24th year.
 Shapes- molars 3/3, premolars 2/2, canine 1/1,
incisors 2/2.

26. FUNCTIONS OF TEETH:
 Incisor and canine teeth
have cutting surface & are
used for biting off pieces
of foods.
 Whereas the premolar &
molar have broad & flat
surfaces & are used for
chewing food.

27. STRUCTURE OF TOOTH
 The shape of the
different teeth vary,
the structure is the
same & consists of
 The crown- the part
that protrudes from the
gum.
 The root- the part
embedded in the bone.
 The neck- slightly
narrowed reason
where the crown
merges with the root.

28. SALIVARY GLAND
Salivary gland releases their secretion into ducts that lead
into the mouth.
There are 3 main pairs
 Parotid gland
 The submandibular glands
 Sublingual glands

29. a) PAROTIDGLAND
 These are situated one on each side of the face just below
the external acoustic meatus. Each gland has a parotid
duct opening into the mouth at the level of the second
upper molar tooth.
B) SUBMANDIBULAR GLAND
 These lie one on each side of the face under the angle of
the jaw. The two submandibular ducts open on the floor
of the mouth, one on each side of the frenulum of the
tongue.

30. C) SUBLINGUALGLANDS:
 These glands lie under the mucous membrane of the
floor of the mouth in front of the sub-mandibular glands.
These have numerous small ducts that open into the floor
of the mouth.

31. STRUCTURE OF THE SALIVARY GLANDS:
 The glands are all surrounded
by the fibrous capsule.
 They consist of a number of
lobules made up of small acini
lined with secretory cell.
 The secretion are poured into
ductiles that join upto form
larger ducts leading into the
mouth.
BLOOD SUPPLY:
Arterial supply is by various
branches from the external
carotid artery and venous
drainage is into the external
jugular veins.

32. COMPOSITON OF SALIVA:
It about 1.5 liters of saliva is produced daily and it
consist of
 Water
 mineral salts
 An enzyme- salivary amylase
 Mucous
 Lysozyme
 Immunoglobulins
 Blood clotting factors

33. FUNCTIONS OF SALIVA:
Chemical digestion of polysaccharides:
Saliva contains the enzyme amylase that begins
the breakdown of complex sugar, including
starch, reducing them to the disaccharides
maltose. The optimum pH for the action of
salivary amylase is 6.8.
 salivary pH ranges from 5.8 -7.4 depending
upon the rate of flow.
Lubrication of food: Dry food entering the
mouth is moistened and lubricated by saliva
before it can be made into a bolus ready for
swallowing.

34. FUNCTIONS OF SALIVA:
 Cleaning and lubricating: an adequate flow of saliva is
necessary to clean the mouth and to keep it soft, moist
and pliable. It help to prevent damage to the mucous
memvrane by rough or abrasive food.
 Taste: The taste buds are stimulated only by chemical
substances in solution & therefore dry fruits only
stimulated the sense of taste after through mixing with
saliva.

35. PHARYNX:
 Pharynx is divided for descriptive purpose into three
parts, the nasopharynx, oropharynx and laryngopharynx.
The nasopharynx is important in respiration.
 The oropharynx & laryngopharynx are passage common
to both the respiratory and the digestive system. Food
passes from the oral cavity into the pharynx then to the
esophagus below, with which it is continuous.

36. BLOOD SUPPLY OF PHARYNX
 The blood supply to the pharynx is by several
branches of the facial arteries. The venous
drainage is into the facial veins and internal
jugular veins.
NERVE SUPPLY:
 This is from the pharyngeal plexus and consist of
parasympathetic and sympathetic nerve.
Parasympathetic supply is mainly by the
glossopharyngeal and vagous nerves and
sympathetic from the cervical ganglia.

37. OESOPHAGUS:
 The oesophagus is about 25 cm long and about 2cmm in
diameter and lies in the median plane in the thorax in
front of the vertebral column behind the trachea and the
heart

38. STRUCTURE OF OESOPHAGUS:
 There are four layers of tissue .As the
oesophagus is almost entirely in the thorax the
outer covering ,the adventitia ,consist of elastic
fibrous tissue that attaches the oesophagus to the
surrounding structure .
 The proximal third is lined by stratified
squamous epithelium and distal third by
columnar epithelium .the middle third is lined by
a mixture of the two.

39. BLOOD SUPPLY
Arterial- The thoracic region is supplied
mainly by the paired oesophagus arteries
,branches from the thoracic aorta. The abdominal
region is supplied by branches from the inferior
phrenic arteries and the left gastric branches of
the celiac artery.

40. VENOUS DRAINAGE
 From the thoracic region venous drainages is in
to the azygos and hemiazygos vein. There is a
venous plexus at the distal end that links the
upward and downward venous drainages, the
general and portal circulation.

41. STOMACH
 The stomach is J- shaped dilated portion of the
alimentary tract situated in the epigastric
,umbilical and left hypochondriac regions of the
abdominal cavity.

42. STRUCTURE OF THE STOMACH
 The stomach is
continuous with the
oesophagus at the
cardiac sphincter and
with the duodenum at
the pyloric sphincter .
 It has two curvatures
,the lesser curvature is
short
 Just before the pyloric
sphincter it curve
upwards to complete
the J- shape .

43. STRUCTURE OF THE STOMACH
 Where the oesophagus join the stomach the
anterior region angles acutely upwards ,curves
downwards forming the greater curvature and
then slightly upwards the pyloric sphincters.
 The stomach is divided in to three regions :the
fundus ,the body and the antrum. At the distal
end of the pyloric antrum is the pyloric
sphincter, is relaxed and open ,and when the
stomach contains food the sphincter is closed.

44. ORGANS ASSOCIATED WITH THE STOMACH
 Anteriorly - left lobe of liver and anterior
abdominal wall.
 Posteriorly – abdominal aorta, pancreas
,spleen,left kidney and adrenal glands.

45. ORGANS ASSOCIATED WITH THE STOMACH
 Superiorly- diaphragm, oesophagus and left lobe of
liver.
 Inferiorly- transverse colon and small intestine
 To the left- diaphragm and spleen.
 To the right- liver and duodenum.

46. WALLS OF THE STOMACH
The four layers of tissue that comprise the basic
structure of the alimentary canal are found in the
stomach but with some modifications.

47. MUSCLES LAYER-
This consists of
three layers of
smooth muscles
fibers
 An outer layer of
longitudinal fibers
 A middle layer of
circular fibers.
 An inner layer of
oblique fibers.

48. BLOOD SUPPLY
Arterial supply to the stomach is by the left
gastric artery , and branch of the coeliac artery
,the rights gastric artery and the gastroepiploic
arteries. Venous drainages is through veins of
corresponding names into the portal veins .

49. FUNCTIONS OF THE STOMACH
These includes
 Temporary storage allowing time for the digestive
enzyme, pepsin, to act.
 Enzyme digestion- pepsin convert protein to peptides .
 Mechanical breakdown- the three smooth muscle layer
able the stomach to act as a churn, gastric juice is added
and the contents are liquefied to chyme. Motility &
secretion are increased by parasympathetic nerve
stimulation.

50. FUNCTIONS OF THE STOMACH
 Limited absorption of water, alcohol & some
lipid soluble drugs.
 Known, specific defense against microbes-
provided by hydrochloride acid into gastric
juice.
 Production & secretion for intrinsic factor
needed for absorption of vitamin b12 in the
terminal ileum.
 Regulation of the passage of gastric contents into
the duodenum.
 Secretion of the gastric hormones .

51. SMALL INTESTINE
 The small intestine can be divided into 3 major regions:
 The duodenum is the first section of intestine that
connects to the pyloric sphincter of the stomach. It is the
shortest region of the small intestine, measuring only
about 10 inches in length.

52. SMALL INTESTINE
 The jejunum is the middle section of the small
intestine that serves as the primary site of
nutrient absorption. It measures around 3 feet in
length.
 The ileum is the final section of the small
intestine that empties into the large intestine via
the ileocecal sphincter. The ileum is about 6 feet
long and completes the absorption of nutrients
that were missed in the jejunum.

53. SMALL INTESTINE
 The small intestine (or small bowel) is the part
of the gastrointestinal tract.
 The small intestine is a long, highly convoluted
tube in the digestive system that absorbs about
90% of the nutrients from the food we eat.
 It is given the name “small intestine” because it
is only 1 inch in diameter, making it less than
half the diameter of the large intestine.
 The small intestine is, however, about twice the
length of the large intestine and usually measures
about 10 feet in length.

54. THE SMALL INTESTINE
It is made up of four layers of tissue
 Mucosa -The mucosa forms the inner layer of
epithelial tissue and is specialized for the
absorption of nutrients from chyme.
 Sub mucosa layer -Deep to the mucosa is
the sub mucosa layer that provides blood
vessels, lymphatic vessels, and nerves to
support the mucosa on the surface.

55. LAYERS OF SMALL INTESTINE
 Muscularis layer -Several layers of smooth
muscle tissue form the muscularis layer that
contracts and moves the small intestines.
 Serosa- it forms the outermost layer of
epithelial tissue that is continuous with the
mesentery and surrounds the intestines.

56. FUNCION OF SMALL INTESTINE
1. Onward movement of its contents by
peristalsis, which is increased by
parasympathetic stimulation.
2. A secretion of intestinal juice, also increase
by parasympathetic stimulation.
3. Completion of chemical digestion of
carbohydrate, protein and fat in the
electrolytes of the villi.
4. Secretion of the hormones cholesystokinin
(CCK) .
5. Absorption of nutrients.

57. LARGE INTSTINE
It consists of the
following parts:
 1. Caecum
 2. The ascending
colon
 3. The transverse
colon
 4. The descending
colon
 5. The pelvic or
sigmoid colon
 6. The Rectum
 7. The anal canal

58. LARGE INTSTINE
 Large intestine, posterior section of the intestine,
consisting typically of four regions:
the cecum, colon, rectum, and anus.
 The large intestine is wider and shorter than
the small intestine(approximately 1.5 meters, or
5 feet it begins in the right iliac region of
the pelvis, just at or below the waist, where it is
joined to the end of the small intestine.
 It then continues up the abdomen, across the
width of the abdominal cavity, and then down to
its endpoint at the anus.

59. LARGE INTSTINE
 The caecum is the first part of the colon and is a
dilated portion which has a blind lower end and
is continuous above with the ascending colon.
Just below the junction of the two, the ileocaecal
valve opens. This valve is a sphincter and
prevents the caecal contents passing back into
the ileum.

60. LARGE INTSTINE
 The Vermiform appendix is a fine tube closed at
one end, which opens out of the caecum, about 2 cm
below the ileo-caecal valve. It is usually about 13
cm (5 inches) long and has the same structure as the
walls of the colon but contains more lymphoid
tissues.

61. LARGE INTSTINE
The ascending colon passes upwards from the
caecum to the level of the liver where it bends
acutely to the left of at the right colic flexure to
become the transverse colon.
The transverse colon is about 50 cm in length
and passes across the abdomen to the under
surface of the spleen. Where it forms the left
colic flexure, by bending acutely downwards to
become the descending colon.

62. LARGE INTSTINE
 The descending colon is about 25 cm in length
and passes down the left side of the abdomen to
the inlet of the lesser pelvis, where it becomes
the sigmoid colon.
 The pelvic or sigmoid colon has an S-shaped
curve in the pelvis and it continues downwards
to become the rectum.
 The Rectum is about 12 cm long and is a
slightly dilated part of the colon. It leads from
the pelvic colon and terminates in the anal canal.

63. THE ANAL CANAL
It is a short canal about 3.8 cm (11/2 inches) long in
adults and leads from the rectum to the exterior.
 There are two sphincter muscles which controls the
anus- The internal sphincter surrounds the upper
the three quarters of the canal and consists of
smooth muscle fibers.
 The external spinster and consists of striated
muscle. It is the tone of these sphincters which
keep the anal canal and the anus Closed.

64. STRUCTURE
In structure, the large intestine consists of the same four
layers of the alimentary canal as described above with a
few modifications.
 The arrangement of the longitudinal muscle fiber is
modified in the colon. They do not form a smooth
continuous layer of tissues, but are collected into three
bands called taenia coli situated at regular intervals
round the colon.

65. STRUCTURE
 These bands are shorter than the other layers of
the large intestine and so produce a typical
puckered or sacculated appearance.
 In the sub mucous layer, there are more
lymphoid tissues than in any other part of the
alimentary canal.
 The mucus lining of the colon and the upper
part of the rectum contains large number of
goblet cells, which secrets mucus.

66. FUNCTIONS OF LARGE INTESTINE
Functions are:
1. Absorption:
 In the colon, water, mineral, salts and some
drugs are absorbed into the blood capillaries.
2. Secretion:
 Colon has only one secretion, mucin which
lubricates the feces and facilitates their passage
through the rectum and anus.

67. FUNCTIONS OF LARGE INTESTINE
3. Digestion:
 Many bacteria are present here which act on
various food residues which have not been
digested or absorbed in the small intestine.
4. Excretion:
 Excess of calcium, iron and drugs of heavy
metals, such as bismuth, are excreted from the
walls of the large intestine and mix with the
feces.

68. FUNCTIONS OF LARGE INTESTINE
 Defecation:
Defecation is the process of emptying the rectum
or the passage of feces out of the body. This is
achieved by the gastro-colic reflex, which occurs
by reflex action with the infant whereas in
adults, is under the control of the will and is
carried out in response to the desire to empty the
bowel produced by distension of the rectum with
feces.

69. PANCREAS
 The pancreas is a pale grey gland waiting about 60gms.
It is about 12-15 cm long & is situated in the epigastric
& left hypochondriac region of the abdominal cavity. It
consist of a broad head , a body & a narrow tale. The
head lies in the curve of the duodenum, the body behind
the stomach & the tale lies in the front of the left kidney
& just reaches the spleen.

70. PANCREAS
 The pancreas is both an endocrine and exocrine gland.
Exocrine Endocrine
Description Large number of
lobes, each drained by
a tiny duct
Ducts eventually unite
to form the pancreatic
duct, which opens into
the duodenum
Groups of specialised
cells (pancreatic islets/
islets of Langerhans)
with no ducts
Hormones diffuse
directly into the blood
as glands have no
ducts
Function Production of
pancreatic juice
containing enzymes
that digest
carbohydrates,
proteins and fats
Secretes hormones,
insulin and glucagon
which are principally
concerned with the
regulation of blood
glucose levels

71. LIVER
 Liver is the largest gland in the body, weighing
between 1 and 2.3 kg. It is situated in the upper
part of the abdominal cavity.

72. ORGANSASSOCIATEDWITHTHE LIVER
 Superiorly & anteriorly- diaphragm and anterior
abdominal wall.
 Inferiorly- stomach, bile ducts, duodenum,
hepatic flexure of the colon, right kidney &
adrenal gland
 Posteriorly- oesophagus, inferior vanacava,
aorta, gall bladder, vertebral column &
diaphragm.
 Laterally- lower ribs & diaphragm.

73. ORGANSASSOCIATEDWITHTHELIVER

74. LIVER
 Liver has four lobes. The two most obvious are
the large right lobe & the smaller, wedge shaped
left lobe. The other two, caudate and quadrate
lobe, are area on the posterior surface.
 BLOOD SUPPLY
The hepatic artery & the portal vein take blood to
the liver. Venous return is by a variable number
of the hepatic veins that leave the posterior
surface & immediately enter the inferior vena
cava just below the diaphragm.

75. STRUCTURE
 The lobes of the liver are made up of tiny
functional units called lobules, which are just
visible to the naked eye. Liver lobules are
formed by cubicle- shaped cells, the hepatocytes.
 Between two pairs of columns of cells are
sinusoids which containing a mixture of blood
from the tiny branches of the portal vein and
hepatic artery.
 This arrangement allows the arterial blood and
portal venous blood to mix and close contact
with the liver cells.

76. FUNCTIONS OF LIVER
 Carbohydrate metabolism
 Fat metabolism
 Protein metabolism
 Breakdown of erythrocytes and defense against
microbes.
 Detoxification of drug & noxious substance-
e.g., alcohol & toxin produced by microbes.
 Intoxification of hormones.

77. FUNCTIONS OF LIVER
 Production of heat
 Secretion of bile.
 Storage- the substances include
 Glycogen
 Fat soluble vitamins- A, D, E, K.
 Iron, copper
 Some water soluble vitamins- vitamin B12.

78. BILIARY TRACT
BILE DUCTS
 The right & left hepatic ducts join to form the
common hepatic duct just outside the portal
fissure.
 The hepatic ducts passage downwards for about
3 cm where it is joined at an acute angle by the
cystic duct from the gall bladder.
 The common bile duct is around 7.5 cm long and
has a diameter of about 6mm.

79. STRUCTURE
 The walls of the bile ducts have the same layers of tissue
as those described in the basic structure of the alimentary
canal. In the cystic duct the mucous membrane lining is
arranged in irregular circular folds, which have the effect
of a spiral bulb.

80. GALL BLADDER
 The gall bladder is a pear-shaped sac attached to
the posterior surface of the liver by connective
tissue. It has a fundus or expended and, a body
or main part and a neck, which is continues with
the cystic duct.

81. STRUCTURE OF GALL BLADDER
 The gall bladder has the same layer of tissue as those
described in the basic structure of the alimentary canal,
with some modifications. There are three layers
 Peritoneum
 Cover only the inferior surface
 Muscle layer
 This is an additional layer of oblique muscle fiber.
 Mucus membrane
 Displays small rugae, when the gall bladder is empty that
disappears when it is distended with bile.

82. FUNCTION OF GALL BLADDER
 Reservoir for bile.
 Concentration of the bile by upto 10- or 15- fold,
by absorption of water through the walls of the
gall bladder.
 Release of stored bile.

83. THE MAJOR DIGESTIVE ENZYMES AND
SECRETION
 Enzymes that digest carbohydrates
ENZYME
SECRETION
ENZYME SOURCE DIGESTIVE ACTION
Ptyalin Salivary glands Starch to dextrin,
maltose,glucose
Amylase Pancreas and intestinal
mucosa
Starch to dextrin,
maltose, gluccose
Maltase Intestinal mucosa Dextrin to maltose and
glucose
Sucrase Intestinal mucosa Sucrose to glucose and
fructose
Lactase Intestinal mucosa Lactose to glucose and
galactose

84. ENZYMES THAT DIGEST PROTEINS
ENZYME
SECRETION
ENZYME SOURCE DIGESTIVE ACTION
Pepsin Gastric mucosa Protein to polypeptides
Trypsin Pancreas Proteins and
polypeptides to
dipeptides and amino
acids
Aminopeptidase Intestinal mucosa Polypeptides to
dipeptides and amino
acids
Dipeptidase Intestinal mucosa Dipeptides and amino
acids
Hydrochloric acid Gastric mucosa Protein to polypeptidase
and amino acids

85. ENZYMES THAT DIGEST FATS
ENZYME
SECRETION
ENZYME SOURCE DIGESTIVE ACTION
Pharyngeal lipase Pharynx mucosa Triglycerides to fatty
acids , diglycerides and
monoglycerides
Steapsin Gastric mucosa Triglycerides to fatty
acids , diglycerides and
monoglycerides
Pancreatic lipase Pancreas Triglycerides to fatty
acids , diglycerides and
monoglycerides
Bile liver Fat emulsification

86. DIGESTIVE DIAGNOSTIC
PROCEDURES

87. HOW IS A DIGESTIVE DISORDER DIAGNOSED
 In order to reach a diagnosis for digestive disorders, a
thorough and accurate medical history will be taken by
your doctor, noting the symptoms you have experienced
and any other pertinent information. A physical
examination is also done to help assess the problem more
completely.
 Some patients need to undergo a more extensive
diagnostic evaluation, which may include laboratory
tests, imaging tests, and/or endoscopic procedures. These
tests may include any, or a combination of, the
following:

88. LABORATORY TESTS
 Fecal occult blood test. A fecal
occult blood test checks for hidden
blood in the stool. It involves
placing a very small amount of
stool on a special card, which is
then tested in a laboratory.
 Stool culture. A stool culture
checks for the presence of
abnormal bacteria in the digestive
tract that may cause diarrhoea and
other problems..

89. IMAGING TESTS
 Barium meal. During this
test, the patient eats a
meal containing barium
allowing 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 doctor
an idea of how well the
stomach is working and
helps to detect emptying
problems.

90. 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, and the movement of the markers
through the colon is monitored with abdominal X-rays taken
several times three to seven days after the capsule is
swallowed

91. COMPUTED TOMOGRAPHY SCAN (CT OR CAT
SCAN)
 This diagnostic
imaging procedure uses
a combination of X-
rays and computer
technology to
produce horizontal, or
axial, images (often
called slices) of the
body.
 A CT scan shows
detailed images of any
part of the body,
including the bones,
muscles, fat, and
organs. CT scans are
more detailed than
general X-rays.

92. 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 examination, 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 doctor
studies the X-rays to determine if anorectal problems occurred while
the patient was emptying the paste from the rectum.

93. LOWER GI (GASTROINTESTINAL) SERIES
(ALSO CALLED BARIUM ENEMA).
 A lower GI series is a procedure that examines the rectum, the
large intestine, and the lower part of the small
intestine. Barium is given into the rectum as an enema. An X-
ray of the abdomen shows strictures (narrowed areas),
obstructions (blockages), and other problems.

94. MAGNETIC RESONANCE IMAGING (MRI).
 MRI is a diagnostic procedure 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.
The machine takes a series of pictures of the inside of the
body using a magnetic field and radio waves

95. MAGNETIC RESONANCE
CHOLANGIOPANCREATOGRAPHY (MRCP).
 This test uses magnetic resonance imaging (MRI) to
view the bile ducts. The machine uses radio waves and
magnets to scan internal tissues and organs.

96. OROPHARYNGEAL MOTILITY (SWALLOWING)
STUDY
 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

97. 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.

98. 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. Ultrasounds
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

99. UPPER GI (GASTROINTESTINAL) SERIES
(ALSO CALLED BARIUM SWALLOW)
 Upper GI series is a diagnostic test that examines the organs of the
upper part of the digestive system: the esophagus, stomach, and
duodenum (the first section of the small intestine). Barium is
swallowed and X-rays are then taken to evaluate the digestive
organs.

100. ENDOSCOPIC PROCEDURES
 Colonoscopy. Colonoscopy is a procedure that allows the doctor to
view the entire length of the large intestine (colon), and can often
help identify abnormal growths, inflamed tissue, ulcers, and
bleeding. It involves inserting a colonoscope, a long, flexible,
lighted tube, in through the rectum up into the colon. The
colonoscope allows the doctor to see the lining of the colon, remove
tissue for further examination, and possibly treat some problems that
are discovered.

101. ENDOSCOPIC RETROGRADE
CHOLANGIOPANCREATOGRAPHY (ERCP).
 ERCP is a procedure that allows
the doctor to diagnose and treat
problems in the liver, gallbladder, bile
ducts, and pancreas. The procedure
combines X-ray and the use of an
endoscope, a long, flexible, lighted tube.
 The scope is guided through the patient's
mouth and throat, then through the
esophagus, stomach, and duodenum .
 A tube is then passed through the scope,
and a dye is injected that will allow the
internal organs to appear on an X-ray.

102. ESOPHAGOGASTRODUODENOSCOPY (ALSO
CALLED EGD OR UPPER ENDOSCOPY).
 An EGD is a
procedure that allows
the doctor to examine
the inside of the
esophagus, stomach,
and duodenum with an
endoscope, which is
guided into the mouth
and throat, then into
the esophagus,
stomach, and
duodenum. It is also
used to take sample
for biopsy.

103. SIGMOIDOSCOPY.
 A sigmoidoscopy is a diagnostic procedure that allows the
doctor 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.

104. OTHER PROCEDURES
 Anorectal manometry. This
test helps determine the
strength of the muscles in
the rectum and anus.
 Anorectal manometry is
helpful in evaluating
anorectal malformations and
Hirschsprung's disease,
among other problems. A
small tube is placed into the
rectum to measure the
pressures exerted by the
sphincter muscles that ring
the canal.

105. ESOPHAGEAL MANOMETRY
 This test helps determine
the strength of the
muscles in the
esophagus.
 It is useful in evaluating
gastroesophageal reflux
and swallowing
abnormalities.
 A small tube is guided
into the nostril, then
passed into the throat,
and finally into the
esophagus. The pressure
the esophageal muscles
produce at rest is then
measured.

106. ESOPHAGEAL PH MONITORING.
 An esophageal pH monitor measures
the acidity inside of the esophagus. It is
helpful in evaluating gastroesophageal
reflux disease . A thin, plastic tube is
placed into a nostril, guided down the
throat, and then into the esophagus.
The tube stops just above the lower
esophageal sphincter, which is at the
connection between the esophagus and
the stomach.
 At the end of the tube inside the
esophagus is a sensor that measures
pH, or acidity. The other end of the tube
outside the body is connected to a
monitor that records the pH levels for a
24- to 48-hour period. Normal activity is
encouraged during the study, and a
diary is kept of symptoms experienced,
or activity that might be suspicious for
reflux, such as gagging or coughing, and
any food intake by the patient.

107. CAPSULE ENDOSCOPY
 This procedure is helpful in identifying
causes of bleeding, detecting polyps,
inflammatory bowel disease, ulcers, and
tumors of the small intestine. A sensor
device is placed on a patient's abdomen
and a PillCam is swallowed.
 The PillCam passes naturally through the
digestive tract while transmitting video
images to a data recorder. The data
recorder is secured to a patient's waist by a
belt for eight hours. Images of the small
bowel are downloaded onto a computer
from the data recorder.
 The images are reviewed by a doctor on a
computer screen. Normally, the PillCam
passes through the colon and is eliminated
in the stool within 24 hours.

108. GASTRIC MANOMETRY
 This test measures electrical and muscular activity in the
stomach. The doctor passes a thin tube down the patient's
throat into the stomach. This tube contains a wire that
takes measurements of the electrical and muscular
activity of the stomach as it digests foods and liquids.
This helps show how the stomach is working, and if
there is any delay in digestion