The major functions of the
gastrointestinal tract are digestion of food, this is where food particle are
broken-down and the other major function is absorption this is when food is
transferred into the circulatory system to the cells for further use.
The various parts of the
gastrointestinal tract (GIT) includes:-
1.
Mouth (oral cavity,
tongue)
2.
Teeth (inceision,
molar and cuspids)
3.
Salivary
(parotid, sublingual and submaxillary)
4.
Pharynx (nasal,
oral, langngeal)
5.
Esophagus.
6.
stomach (fundus, rugae,
cardial sphincter, and pyloric sphincter)
7.
small intestines
(duo denum, jejunum, and deam)
8.
Large intestines
(cecum, ascencling colon tranverse desending colon, sigmoid, rectum and anus).
Functions of the parts of the (GIT)
gastrointestinal tract
1.
The Mouth:- The
mouth aids in chewing where the tongue contain the taste buds.
2.
Salivary Glands:-
Which moisten food, beginning the conversion of starches to sugars and
lubricates the food as it travels through the Gastrointestinal tract (GIT).
3.
Pharnyx:- aids in
the travel of the food while
4.
The Esophagus
secrets mucus to aid the movement of food and serves in a passage way for food
to enter the stomach.
5.
The Stomach:- The
stomach begins the digestion of protein, serves as a reservoir for food for 3-4
hours and also turns solid forms of food into a semi-liquid form called CHYME.
in the stomach excretes to aid in digestion and absorption of needed nutrient
and vitamins the stomach contain HCL acid (strong acid) that aids in the
digestion of meats and protects us from foreign organisms, pepsin for the digestion of proteins, intrinsic
factor aids in the absorption of B12, mucin protects the stomach lining and
water is a solvent that aid in digestion.
6.
The small
intestines are the longest part of the G.I tract and this is where 90% of
digestion takes place. The wall of the duodenum secretes mucus to neutralize
acids.
7.
Large
intestines:- The large intestine has two primary functions absorption and
storage.
8.
Anal canal:- aid
in defecation which consist of unabsorbed food, bacteria and cell debris)
Disorders in the gastrointestinal tract
and drug therapy for the disorder.
1. Indigestion:- The sufferer of gastric
discomfort must be certain that self-medication is appropriate, if so
determined several therapeutic approaches can be used to alleviate the problem.
Non- medicinal approach (minimize acid
rebound)
The stomach will pump out increased
amounts of acid and juices following the consumption of all food and drinks (that
includes bland foods and milk products). This causes increased gastric
irritation 1-3 hours after eating or drinking, thus midnight snacks will result
in early morning stomach discomfort because of the amount of acid rebound to
avoid substance that stimulate gastric secretions.
Avoid emotional situations that enhance
gastric activities.
Medical Approach
The medication for the treatment of indigestion comes
in a variety of forms depending on the cause of the gastric irritation the
primary agents used for self- medication are classified as ANTACIDS these products may be promoted for an upset
stomach caused by:-
a. Heartburn
b. Sour
stomach
c. acid
indigestion
Note:
That all antacids are relatively safe if used by healthy people but regular
daily use can cause problem which can cause bowel irregularities (constipation
or diarrhea)
2. Constipation:- laxatives are commonly
used to accelerate the movement of food through the gastrointestinal tract. Laxatives
the potential for loss of pharmacologic effect of poorly absort delayed acting
and extended-release oral preparation by accelerating their transit through the
intestine.
These drug can be classified into six
but I will mention three(3).
a. irritants and stimulants
i. SENNA: This agent is a widely used
stimulant laxative- its active ingredient is a group of sennosides, a natural
complex of an thraquinone gloycoside. Taken orally, Senna causes evacuation of
the bowels within 8 to 10 hours. In combination product with a docusate
containing stool softener, it is useful in treating constipation mostly opioid-
included constipation.
ii. BISACODYL: Available as suppositories
and enteric-coated tablets bisacodyl is a potent stimulant of colon. It acts directly
on nerve fibers in the mucosa of the colon adverse effects include abdominal
cramps and the potential for atonics colon with prolonged use. Avoid taking
milk and drug like (antacids, ppls, and H2 – reception antagonists)
at same time as the enteric-coated tablet in rmaturely of the enteric–coated
tablet in the stomach resulting to stomach ach irritation and pain.
iii. Castor
oil:-This agents is broken down in the small intestine to ricinoleic acid,
which is very irritating to the stomach and promptly increases peristalsis.
Pregnant patients should avoid castor oil because it may stimulate uterine
contractions.
b. Bulk
laxatives
The bulk laxatives include hydrophilic colloids (from
indigestible parts of fruits and vegetables). They form gels in the large
intestine, causing water retention and intestinal distention thereby increasing
peristaltic activity similar actions are produced by methylcellulose, psyillum
seeds, and bran. They should be used cautiously in patients who are immobile
because of their potential for causing intestinal obstruction.
c. Lubricant
Laxatives
Mineral oil and glycerin suppositories are considered
to be lubricants and act by facilitating the passage of bard stools. Mineral
oil should be taken orally in an upright position to avoid its aspiration and potential for lipid or lipoid pneumonia.
3. DIARRHEA:-
Anti-diarrheals increased motility of the gastrointestinal tract and decreased
absorption of fluid are major factors in diarrhea. Anti diarrheal drugs used to
treat diarrhea such as acute diarrhea include antimotility agents adsorbents
and drugs that modify fluid and electrolyte transport.
a. Antimotility agents
Two drugs that are widely used to
control diarrhea are diphenoxylate and coperamide.
Both are analogs of meperidine and have opioid -like
action on the gut, they activate presynaptic opioid receptors in the enteric
nervous system to inhibit acetycholine release and decrease peristalsis. At the
usual doses, they lack analgesic effects. Side effect includes drowsiness,
abdominal cramps and dizziness because these drugs can contribute to toxic megacolon,
they should not be used in young children or in patients with severe colitis.
b. Adsorbents
Adsorbent agents, such as aluminum hydroxide
and methylcellulose are used to control diarrhea – presumably these agents act
by adsorbing intestinal toxins or microorganisms and/or by coating or
protecting the intestinal mucosa.
They are much less effective than
antimotility agents and they can interfere with the absorption of other
drugs.
c. Agents that modify fluid /electrolyte
transport
Bismuth subsacicylate, used for
traveler’s diarrhea, decrease fluid secretion in the bowel its action may be
due to its salicylate component as well as its coating action. Adverse effect
may include black tongue and black stools.
4. LEAKY
GUT SYNDROME: are clinical disorder associated with increased intestinal
permeability. They include:-
a. Inflammatory and infections bowel
diseases
b. Chronic inflammatory arthritides
c. Cryptogenic skin condition like:-
i. acne
ii. Psoriasis
iii. Dermatitis herpetiformis
iv. Eczema
v. Urticaria
vi. Pancreatic carcinoma
vii. Chronic Pancreatitis
Treatment of increased intestinal
permeability (hyperpameability)
1. Remove the cause: This includes the
treatment of an intestinal infection avoidance of entero-toxic drugs (primarily
NSAIDS and ethanol) and elimination of food allergens from the diet. Diagnostic
methods for food allergy are controversial and a discussion of the merit and
pitfalls of each method is beyond the scope of this chapter.
2. Nourish the gut:- under normal
condition, intestinal epithelium has the fastest rate of mitosis of any tissue
in the body. The body (epithelium cell) requires protein, calories and
essential fatty acid to repair old cell slough and generate a new epithelium, every
three to six drugs so as to heal the damaged tissue or cell when they are not
met hyperpermeability will exacerbates to maintain its integrity.
3. Glutamine: among all the amino acids
appear to have a special role in restoring normal small bowel permeability and
immune function. Patients with intestinal mucosal injury secondary to
chemotherapy or radiation benefit from glutamine supplementation with less
villous atrophy. Increased mucosal healing and decreased passage of endotoxin
thing of the gut wall.
4. Ulcerative colitis: The treatment of
patient with antibiotics followed by administration of non-pathogenes,
standardized E-coli strains may induce and help to maintain remission, other
probiotic therapies have not been tested in controlled trials although pouchitis
(post inflammation of the heal pouch) has been shown to respond to respond to
very high doses (450 billion C FUs/ day or more) of a mixture of lactic acid
and bifidobacteria. Thus preparation is now being tested as an aid to
maintenance of remission in patients with ulcerative colitis.
5. Acid-
peptic Disease
Hydrochloric acid produces much of the cellular damage
and symptomatology of peptic ulcer diseases gastritis and gastroesopheigeal
reflux disease, gas tropathy, atrophic gastritis and gastric lymhoms the
treatment involves eradication of H. pylori with antibiotics and ppls has
revolutionized conventional treatment of these conditions.
Several natural products have been
advanced as alternatives to antibiotics, but evidence to support the use is
minimal. Example includes pastitia lentiscus resin or mastin gum which is used
as food component in the mediterranean and as treatment of gastric disorders by
the traditional healers. It kills H. pylori in vitro at concentrations
equivalents to administration of 1000mg twice a day. These ppls: inhibitors of
the H+ /k+ ATpase proton pump used in suppressing acid
production and healing peptic-ulcers has made them, they preferred drugs for
stress ulcer treatment and prophylaxis, treating erosive esophagitis and active
duodenal ulcer and long term treatment of pathologic hypersecretroy conditions
(for example, zollinga – Eclison syndrome in which a gastric –producing tumor
causes hypersecretion of Hct) They are also appoved for the treatment of GERD
and have gained favour over H2 antagonist. It reduces risk of
bleeding from a ulcer, caused by aspirin and other NSAID.
Finally it should be taken 30 to 60
minutes before breakfast or the largest meal of the day and if H2 –
receptor antagonist is needed it should be taken well after the ppls for best
effect because the H2 antagonist will reduce the activity of the
proton pumps in adverse effect the ppls are generally well tolerated.
6. Irritable
bowel Syndrome (IBS)
Irritable bowel syndrome (also called
spastic colon or nervous stomach) is a condition in which the colon muscle
contracts more readily than in people without IBS. A number of factor can
trigger IBS including certain foods, medicines and emotional stress symptoms of
IBS includes abdominal pain and cramps, excess gas, bloating, and a change in bowel habits such
as harder, looser or more urgent stools than normal. Often people with IBS have
alternating constipation and diarrhea.
Treatment of
irritable bowel syndrome
Treatment includes avoiding caffeine, increasing fiber
in the diet, monitoring which foods trigger IBS (and avoiding these foods)
minimizing stress or learning different ways to cope with stress and sometimes
taking medicines as prescribed by your health care provider.
7. Anal
disorder (Hemorrhoids)
Hemorrhoids are swollen blood vessels that line the
anal opening caused by chronic excess pressure from straining during a bowel
movement, persistance diarrhea or pregnancy. These disorder is classified into
two:-
1.
Internal
hemorrhoids
2.
external
hemorrhoids
Interenal
hemorrhoids:- are normal structures cushioning the lower rectum and protecting its
from damage by stool. When they fall down into the anus as a result of
straining, they become irritated and start to bleed ultimately, internal
hemorrhoids can fall down enough to prolapsed (sink or protrude) out of the
anus.
Treatment
includes
Improving bowel habits (such as avoiding constipation,
not straining during bowel movements and moving your bowels when you have the
urge) using elastic bands to pull the internal hemorrhoids back into the rectum
or removing them surgically. Surgery is needed only for a small number patients
with very large painful and persistent hemorrhoids.
External Hemorrhoids
External hemorrhoids are veins that lie just under the
skin on the outside of the anus. Some times after straining, the external
hemorrhoidal veins burst and a blood clot forms under the skin. This very
painful condition is called a pile.
Treatment
Includes
Removing the clot and vein under local anesthesia in
the doctor’s office.
8. Dyspepsia: The sensation of difficulty in swallowing. it is a
pain or discomfort located in the upper abdomen (stomach and upper small
intestine)
Treatment of
Dyspepsia
It includes combination of :-
a. diet
b. eradication of H. pylori
c. Acid-lowering medications
d. Prokinetic and antiemetic agents
e. centrally acting therapies
Acid lowering medications
·
H2
blockers such as:-
·
Ranitidine
(zantac)
·
Cimetidine
(tagamet)
·
Nizatidine (axid or
Famotidine
(pepcid) are the initial agent used by many primary care providers and are
marginally better than placebo at improving upper center abdominal (epigastric)
pain, although they do not improve other dyspeptic symptoms. If the H2
blockers fail to improve symptoms most doctor then use a proton pump incubator
(ppls) omeprazole
(prilosec)
lansoprazole
(prevacid)
rabeprazole
(aciphex) pantoprazole
The ppls (proton pump inhibitors)
are approximately 10% better than placebo at improving dyspeptic symptoms.
Centrally Acting Therapies
Much of the control of digestive function and
sensation is under central therapies that targets central control mechanisms,
many have value in relieving symptoms. Tricyclic antidepressants, used in doses
lower than required to treat depression may improve symptoms of dyspepsia in
patients who have failed to benefit from treatment with H2 blockers
or prokinetics. Hypnotherapy may improve dyspeptic symptoms in some patients,
and a recent study found that hypnotherapy was better than medical therapy and
supportive therapy at improving quality of life and symptom shores.
9. Sphincter
of oddi dysfunction
A motility disorder characterized by severe steady
pain with no structural abnormalities that explain the symptoms. It sometimes
occurs following gall bladder removal, but also many occur with an intact gall
bladder. It occur when the sphincter does not relax at the appropriate time
(due to scarring or spasm).
Treatment of sphincter of odidi
dysfunction
Treatment depends on what is found. It may often
involve cutting the muscular sphincter (sphincterotomy) to remove any stones or
to relieve any scarring or spasm of the sphincter.
10. Dysphagia
It is the sensation of solid and/or liquid foods
sticking lodging or passing abnormally through the esophagus. It is diagnosed
based on symptoms present for at least three months and not associated with
anatomic abnormalities gastroesphageal reflux disease (GERD) or well recognized
motility disorders such as adialaia (difficulty swallowing due to an absence of
peristaltic contractions in the esophagus).
Treatment of Dysphagia
For mild symptoms avoidance or reduction of foods that
worsen symptoms is recommended chewing food thoroughly during meals may also
help.
12. Globus
It is a sensation of a lump or ball in the throat
typically felt in the throat at the level of the Adam’s apple. It is commonly
experienced with an intense emotional experience, the disorder involves neck or
throat pain, bleeding from the month or throat, weight loss, pain or difficulty
in shadowing, muscle weakness. Heart burns commonly occur with globus.
Treatment of Globus
There is no specific treatment for glosus beyond the
assurance that it isn’t the sign of a serious disease.
13. Lactose
Intolerance
Is the inability to digest these milk sugar symptoms
are produced when lactose is not adequately absorbed in the digestive tract
(malabsorption) symptoms may include watery stool or diarrhea, abdominal
cramps, gas and/ or bloating experienced after eating drinking lactose
–containing foods and beverages.
Treatment of lactose Intolerance
Individuals who experience symptoms of lactose
intolerance from small amount of lactose- containing foods should look for
words such as “whey”, “lactose”, “nonfat milk solids,” “butter milk”, “malted
milk”, “margarine”, and “sweet” or sour cream” some breads dry cereals, cookies
instant soups, breakfast drinks, and milk chocolate contain small amount of
lactose also lactose is widely used as a filer or diluent (increases bulk) in
tablets and capsules. Ask a pharmacist or if medications you take contain
lactose.
14. Narcotic
Bowel Syndrome
The syndrome is characterized by chronic or periodic
abdominal pain that gets worse when the effect of narcotic drug wear down in
addition to pain which is the primary feature other symptoms may include: Nan
sea, bloating- periodic vomiting, abdominal distention, and constipation.
Treatment of narcotic bowel
syndrome
The UNC group has also developed a treatment approach.
The narcotic is with drawn and
substituted with effective alternative medication to help manage the pain and
bowel symptom until the narcoties are removed from the system. This requires
the doctor and patients working closely together the treatment process usually
takes a week or two in the hospital but
may take several weeks or months outside the hospital to implement it.
14. Short
Bowel Syndrome
Is a group of problems related to poor absorption of
nutrients. It is sometimes known as short gut syndrome (or short gut) or
intestinal failure. It typically occurs in people who have had half or more of
that small intestine removed. Not enough bowel is left to absorb needed
nutrition and fluid. The main cause of short bowel syndrome is surgical removal
of half or more of the small intestine to treat intestinal disease, injuries,
or defects present at birth.
Diarrhea is the main symptom of short bowel syndrome.
Diarrhea can lead to dehydration, malnutrition, and weight loss.
Other symptoms may include: cramping, bloating,
heartburn weakness and fatigue.
Treatment of
short bowel syndrome
The main treatment for short bowel syndrome is
nutritional support. Treatment may involve use of oral rehydration solutions parenteral
nutrition, enteral nutrition and medications.
Long-term treatment and recovery depend in part on
what sections of the small intestine were removed how much remains, and how
well the remaining small intestine adoptions over time.
Intestinal transplantation may be an option for some
patients for whom other treatment have failed and who have complication from long-term
parenteral nutrition. These infection includes blood, infection, blood clots,
and liver failure, which can lead to the need for liver transplantation and it
take 2 year or more years for the intestinal adoption to occur.
15. Volvulus
Is a condition in which the bowel twists on itself,
causing obstruction to the flow of material through the bowel. It can also lead
to obstruction of the blood supply to the intestine itself which can result in
tissue death within the bowel volvulus is most commonly due to a birth defect
called melioration, which is when the bowel becomes misaligned during fetal
development. The bowel do not have a normal attachment to the abdominal wall,
which make it possible for the bowels to shift out of their normal position or
to rotate. Some children with volvulus experience
reducing episodes of vomiting with abdominal pain, which resolve without
treatment. This may be due to a condition known as “intermittent volvulus”,
which occurs when the bowel just happened to twist, then untwist on its own
other symptoms which may occur include:-
a.
Abdominal
tenderness
b.
Nauseas or
vomiting
c.
Vomiting gree
bile looking material
d.
Bloody or dark
red stool
e.
Constipation or
difficulty expecting stools
f.
Shock
Treatment of
Volvulus
Emergency surgery is necessary to repair a
volvulus. An incision is made in the abdominal wall, and the bowels are
untwisted and the blood supply restored. If a small segment of bowel to
necrotic (dead from lack of blood flow) it is removed and the ends of the
healthy bowel are sewn back together or used to form a colostomy or ileostomy
(a tube to the outside through which bowel content can be removed. The term
depend on where the tube is placed). If the entire bowel is necrotic, the outside
look is poor and life threatening.