THE DIGESTIVE SYSTEM

PRESENTED BY:

HARSH RAMAN

M.Sc (N) 1st Year

Roll No-1914703

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.

THE DIGESTIVE SYSTEMThe 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.

HUMAN DIGESTIVE SYSTEM

FUNCTION OF THE DIGESTIVE SYSTEM:

INGESTION

DIGESTION

ABSORPTION

ELIMINATION

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).

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.

ABSORPTION

During

absorption,

nutrients, water

and electrolytes

are transported

from the GIT to

the circulation.

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.

ORGANS OF DIGESTIVE SYSTEMALIMENTARY TRACT

Mouth

Pharynx

Esophagus

Stomach

Small intestine

Large intestine

Rectum and anal

canal

ACCESSORY ORGANS OF DIGESTIVE SYSTEM

Three pairs of

salivary gland

The pancreas

The liver &

biliary tract.

STRUCTURE OF ALIMENTAY CANAL

The walls of the alimentary tract are formed by

4 layers of tissues.

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.

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.

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.

3. Sub mucosa:This layer consists of loose connective tissue,

blood vessels and lymphatics.

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.

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.

THE WALLS OF THE ALIMENTARY TRACT

MOUTH (ORAL CAVITY)

The mouth or oral cavity is lined by mucous

membrane, consisting of stratified squamous

epithelium containing mucus secreting glands.

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.

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 squamousepithelium, with little projection called as papillae, containing taste buds.

FUNCTIONS OF TOUNGE

The term plays an important role in

chewing ( mastication),

swallowing( deglutition),

speech &

taste.

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.

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.

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.

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.

SALIVARY GLANDSalivary gland releases their secretion into ducts that lead

into the mouth.

There are 3 main pairs

Parotid gland

The submandibular glands

Sublingual glands

a) PAROTID GLAND

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.

C) SUBLINGUAL GLANDS:

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.

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 acinilined 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.

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

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.

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.

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.

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.

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

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.

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.

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.

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.

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 .

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.

ORGANS ASSOCIATED WITH THE STOMACH

Anteriorly - left lobe of liver and anterior abdominal wall.

Posteriorly – abdominal aorta, pancreas ,spleen,left kidney and adrenal glands.

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.

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.

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.

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 .

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.

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 .

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.

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.

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.

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.

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.

FUNCION OF SMALL INTESTINE1. 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.

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

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.

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.

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.

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.

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.

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.

STRUCTUREIn 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.

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.

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.

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.

FUNCTIONS OF LARGE INTESTINEDefecation:

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.

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.

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

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.

ORGANS ASSOCIATED WITH THE LIVERSuperiorly & 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.

ORGANS ASSOCIATED WITH THE LIVER

LIVERLiver 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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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

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

DIGESTIVE DIAGNOSTIC

PROCEDURES

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:

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..

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.

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

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.

DEFECOGRAPHY

Defecography is an X-ray of the anorectal area that evaluates completeness of stool elimination, identifies anorectalabnormalities, 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.

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.

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

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.

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

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.

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

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.

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.

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.

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.

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.

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.

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.

ESOPHAGEAL PH MONITORING. An esophageal pH monitor measures

the acidity inside of the esophagus. It is helpful in evaluating gastroesophagealreflux 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.

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 PillCampasses through the colon and is eliminated in the stool within 24 hours.

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