Download Perspectives in Nutrition, 8th Edition

Perspectives in Nutrition, 8th Edition
Chapter 4 Outline: Human Digestion and Absorption
After studying this chapter, you will be able to:
1. Outline the roles played by the gastrointestinal tract and the related accessory organs
(liver, gallbladder, and pancreas) in digestion and absorption.
2. Describe how foods are moved along the digestive tract.
3. Explain the 4 main types of absorption.
4. Identify the key enzymes and hormones involved in digestion and absorption and their
functions.
5. Identify major nutrition-related gastrointestinal diseases and disorders and typical
approaches to prevention and treatment.
6. Explain why diarrhea represents a serious health challenge to infants and young children
around the world.
4.1
Organization of the Human Body
A.
Chemical level: atoms form molecules
B.
Cells
1.
Smallest functional unit of the human body
2.
Grow, absorb nutrients, use energy, synthesize and secrete compounds,
excrete wastes
3.
Require water, building supplies (e.g., amino acids, minerals), chemical
regulators (e.g., vitamins), and energy in the form of adenosine
triphosphate (ATP)
C.
Tissues: groups of similar cells working together to perform a specific task
1.
Epithelial tissue: covers surfaces inside and outside body
a.
Absorbs nutrients
b.
Secretes substances
c.
Excretes waste
2.
Connective tissue
a.
Supports and protects body
b.
Stores fat
c.
Produces blood cells
3.
Muscle tissue: permits movement by contracting and relaxing
4.
Nervous tissue: transmits nerve impulses
D.
Organs: tissue structures that perform specific functions
E.
Organ systems: several organs working together to perform a specific function
(see Table 4-1)
1.
Digestive
F.
4.2
2.
Circulatory
3.
Immune
4.
Nervous
5.
Endocrine
6.
Urinary
7.
Integumentary
8.
Skeletal
9.
Muscular
10.
Respiratory
11.
Reproductive
Organism
Digestive System Overview
A.
General
1.
Digestion: process of breaking down foods into a usable form
2.
Absorption: uptake of nutrients from the GI tract into the blood or lymph
3.
Controlled by hormones and nervous system
4.
GI tract is barrier to entry of harmful bacteria into the body
5.
Healthy bacteria in the large intestine keep pathogenic bacteria under
control, synthesize nutrients and short-chain fatty acids
B.
Anatomy of the GI Tract (a.k.a. alimentary canal)
1.
General
a.
Hollow, muscular tube that extends ~15 feet from mouth to anus
b.
Nutrients pass through walls of the GI tract
i.
Mucosa: innermost layer, lined with epithelial cells, folded
and covered with villi that project into the lumen
ii.
Submucosa: connective tissue, glands, blood vessels, and
nerves
iii.
Muscle: inner layer of circular smooth muscle and outer
layer of longitudinal muscle fibers (stomach has third layer
that runs diagonally)
iv.
Serosa: outermost, protective layer; secretes fluid that
cushions GI tract and reduces friction
c.
Sphincters: ring-like muscle that open and close like valves to
control the flow of GI contents
i.
Lower esophageal sphincter: prevents backflow of stomach
contents into the esophagus
ii.
Pyloric sphincter: controls flow of stomach contents into
the small intestine
iii.
C.
Sphincter of Oddi: controls flow of bile from common bile
duct into small intestine
iv.
Ileocecal sphincter: prevents contents of large intestine
from reentering small intestine
v.
Anal sphincter: controls defecation, under voluntary control
2.
Mouth and salivary glands
a.
Chew food
b.
Perceive taste
c.
Moisten food
d.
Lubricate food
e.
Release starch-digesting enzyme (amylase)
f.
Initiate swallowing reflex
3.
Esophagus
a.
Lubricate
b.
Move food (peristalsis)
4.
Stomach
a.
Store, mix, dissolve, and continue digestion of food
b.
Dissolve food particles with secretions
c.
Kill microorganisms with acid
d.
Release pepsin to digest protein
e.
Lubricate and protect stomach (mucus)
f.
Regulate emptying of dissolved food into small intestine
g.
Produce intrinsic factor for vitamin B-12 absorption
5.
Liver: produce bile to aid fat digestion and absorption
6.
Gallbladder: store, concentrate, and release bile into small intestine
7.
Pancreas: secrete sodium bicarbonate and enzymes to digest carbohydrate,
fat, and protein
8.
Small intestine
a.
Mix and propel contents
b.
Lubricate with mucus
c.
Digestion and absorption of majority of nutrients
9.
Large intestine
a.
Mix and propel contents
b.
Absorb sodium, potassium, and water
c.
House bacteria
d.
Lubricate with mucus
e.
Synthesize some vitamins and short-chain fatty acids
f.
Form feces
10.
Rectum: hold feces and expel via anus
GI Motility: Mixing and Propulsion
1.
D.
Peristalsis: coordinated wave of muscular contractions that mix food with
digestive secretions and propel it along the GI tract
2.
Segmentation: back-and-forth action that breaks apart bolus into smaller
pieces and mixes with digestive juices
3.
Stomach has 3 opposing layers of muscle that contract ~3 X/min
4.
Small intestine contracts every 4 - 5 seconds
5.
Large intestine has slower peristaltic waves that lead to occasional mass
movements, which propel fecal matter toward the rectum for elimination
Digestive System Secretions
1.
Saliva: secreted in mouth
a.
Begins starch digestion
b.
Facilitates swallowing by lubricating, moistening food
2.
Mucus: thick fluid secreted in mouth, stomach, and small intestine
(pancreas)
a.
Protects body cells
b.
Lubricates food
3.
Hydrochloric acid: secreted by stomach
a.
Protein digestion
b.
Destruction of pathogens
c.
Increases solubility of minerals
4.
Digestive enzymes: secreted in mouth, stomach, and small intestine
(pancreas)
a.
Protein molecules that catalyze chemical hydrolysis reactions to
digest foods
b.
Each enzyme has specific target substrate
c.
Majority of digestive enzymes are synthesized by the pancreas and
small intestine
d.
Pancreas adjusts enzyme production to match the macronutrient
content of the diet
e.
Insufficiency of digestive enzymes can lead to incomplete
digestion and limited absorption
f.
Release of digestive enzymes is tightly regulated by nerves and
hormones to prevent autodigestion of the GI tract
i.
Gastrin
ii.
Secretin
iii.
Cholecystokinin
iv.
Gastric inhibitory peptide
5.
Hormones: secreted by stomach and small intestine
a.
Regulate digestion and absorption
6.
Bicarbonate: secreted by pancreas and small intestine
7.
4.3
a.
Neutralizes stomach acid when it reaches small intestine
Bile: produced by liver, stored in gallbladder
a.
Emulsifies fat to aid fat digestion
Moving through the GI Tract: Mouth and Esophagus
A.
General
1.
Food preparation begins the process of digestion
2.
Teeth grind food into smaller particles to increase surface area for
digestion (see Table 4-8)
a.
Incisors
b.
Canine
c.
Premolars
d.
Molars
3.
Tongue mixes food with saliva, creating a bolus
4.
Saliva: dilute, watery fluid containing
a.
Mucus (lubrication)
b.
Lysozyme (kills bacteria)
c.
Amylase (digest starch)
d.
Lingual lipase (digest fats, mainly during infancy)
e.
Substances that prevent tooth decay (antibacterial agents, minerals,
neutralizes acids)
f.
Salivary glands (see Figure 4-8)
i.
Parotid
ii.
Sublingual
iii.
Submandibular
B.
Taste and Smell
1.
Taste-forming compounds in food dissolve in saliva
2.
Taste buds on tongue and soft palate interact with taste compounds in food
3.
5 basic taste sensations
a.
Salty (metal ions)
b.
Sour (acid)
c.
Sweet (sugars)
d.
Bitter (caffeine, quinine, other compounds in fruits and vegetables;
many bitter compounds are toxic, but some are beneficial
phytochemicals)
e.
Umami (mushrooms, cooked tomatoes, MSG, etc)
4.
6 million olfactory cells in the nose enhance the sense of taste
a.
Genetic variation
b.
Affected by diseases and drugs
C.
Swallowing (see Figure 4-9)
1.
2.
3.
Bolus of food is pushed by the tongue against the hard palate, moves
toward the pharynx
Epiglottis: flap at top of esophagus that prevents food from lodging in the
trachea by covering the larynx; breathing stops
Esophageal muscle contractions push bolus toward stomach
4.4
Moving through the GI Tract: Stomach
A.
Bolus moves past lower esophageal sphincter (a.k.a. cardiac sphincter), which
prevents reflux of stomach contents into the esophagus (LES malfunction leads to
heartburn)
B.
Stomach
1.
Capacity
a.
~2 oz when empty
b.
Expands to 4 - 6 cups after a meal
c.
Can hold 16 cups when extremely full
2.
Little digestion occurs in stomach
a.
Some fat digestion
b.
20% of alcohol absorbed
3.
Secretions: 2 c/d of gastric juice
a.
Hydrochloric acid from parietal cells inactivates proteins, destroys
pathogens, dissolves minerals, converts pepsinogen to pepsin
(active protein-digesting enzyme)
b.
Pepsinogen (inactive protein-digesting enzyme) from chief cells
c.
Gastric lipase from chief cells
d.
Gastrin (hormone) controls release of pepsinogen and gastric
lipase; secreted in response to eating or thinking about eating;
secretion declines throughout duration of meal
e.
Mucus from mucous cells on gastric mucosa lubricates and
protects stomach cells from autodigestion
f.
Heavy use of non-steroidal anti-inflammatory drugs can damage
stomach wall because they inhibit prostaglandin production, which
decreases mucus production
g.
Intrinsic factor is required for absorption of vitamin B-12
4.
Contractions of 3 muscle layers mix food with gastric secretions to
transform solid food into chyme
5.
Pyloric sphincter between stomach and duodenum controls flow of chyme
into small intestine
4.5
Moving through the GI Tract: Small Intestine and Accessory Organs
A.
General (see Figure 4-14)
1” diameter
Duodenum: 10” of length
Jejunum: 4’ of length
Ileum: 5’ of length
Circular folds, villi, and microvilli increase surface area for absorption
600X
a.
Goblet cells produce mucus
b.
Endocrine cells produce hormones and hormone-like substances
c.
Enterocytes produce digestive enzymes and absorb nutrients
d.
Brush border of microvilli covered with digestive enzymecontaining glycocalyx
6.
Digestion occurs primarily in duodenum and upper part of jejunum,
requiring secretions from enterocytes, pancreas, liver, and gallbladder
7.
6 c/d of mucus, enzymes, and hormones
Liver, Gallbladder, and Pancreas (accessory organs; see Figure 4-16)
1.
Common bile duct and pancreatic duct empty into the duodenum at the
sphincter of Oddi
2.
Liver produces 2 - 4 c/d of bile
a.
Cholesterol-containing yellow-green fluid
b.
Emulsifies fat into micelles
c.
Reabsorbed in ileum and returned to the liver (enterohepatic
circulation)
3.
Gallbladder stores bile until needed
4.
Pancreas produces 5 - 6 c/d of pancreatic juice
a.
Pancreatic amylase digests starch
b.
Pancreatic lipase digests fat
c.
Proteases digest protein
Gastrointestinal Hormones - a Key to Orchestrating Digestion (see Table 4-3)
1.
Gastrin (stomach and duodenum): trigger release of HCl and pepsinogen,
stimulate intestinal motility
2.
Cholecystokinin (small intestine in response to dietary fat in chyme):
stimulates release of pancreatic enzymes and bile
3.
Secretin (small intestine in response to acidic chyme): stimulates release
of pancreatic bicarbonate
4.
Gastric inhibitory peptide (small intestine as digestion progresses): signals
stomach to limit release of gastric juices, slows gastric motility
5.
Other hormones and hormone-like compounds produced by the GI tract,
pancreas, and brain help to regulate digestion
a.
Vasoactive intestinal peptide
b.
Bombesin
1.
2.
3.
4.
5.
B.
C.
D.
c.
Substance P
d.
Somatostatin
Absorption in the Small Intestine
1.
Absorptive cells migrate from crypts (base of villi) to surface of villi,
maturing as they migrate; shed into the lumen when damaged (2 - 5 days)
2.
Because absorptive cells undergo such rapid turnover, nutrient
deficiencies have a dramatic effect on the health and absorptive capacity
of the small intestine
3.
Sites of absorption (see Figure 4-17)
a.
Stomach
i.
Alcohol (20% of total)
ii.
Water (minor amount)
b.
Small intestine
i.
Calcium, magnesium, iron, other minerals
ii.
Glucose
iii.
Amino acids
iv.
Fats
v.
Vitamins
vi.
Water (70 - 90% of total)
vii.
Alcohol (80% of total)
viii.
Bile acids
c.
Large intestine
i.
Sodium
ii.
Potassium
iii.
Some fatty acids
iv.
Gases
v.
Water (10 - 30% of total)
4.
Types of absorption
a.
Passive diffusion: concentration of nutrient is higher in lumen than
in absorptive cells, nutrient moves into absorptive cells by
diffusion (e.g., fats, water, some minerals)
b.
Facilitated diffusion: nutrients move down concentration gradient,
but require carrier proteins to move into absorptive cells (e.g.,
fructose)
c.
Active absorption: nutrients move against a concentration gradient
and require energy for absorption (e.g., amino acids, glucose)
d.
Endocytosis
i.
Phagocytosis: absorptive cells engulf compounds, form
vesicle
ii.
Pinocytosis: absorptive cells engulf liquids, form vesicle
iii.
e.g., immune substances from breast milk
4.6
Moving Nutrients around the Body: Circulatory Systems
A.
Cardiovascular System (see Figure 4-19)
1.
Absorption of water-soluble nutrients
a.
Proteins
b.
Carbohydrates
c.
Short-chain fatty acids
d.
Medium-chain fatty acids
e.
B-vitamins
f.
Vitamin C
2.
Components
a.
Heart
b.
Blood vessels (arteries, capillaries, veins)
c.
Blood
3.
Flow of cardiovascular system
a.
Right side of the heart accepts oxygen-depleted venous blood
b.
Blood is pumped out of the right side of the heart to the lungs
c.
Blood picks up oxygen and releases carbon dioxide at the lungs
d.
Left side of the heart receives oxygen-rich blood from the lungs
e.
Oxygenated blood is pumped out of the left side of the heart to the
body cells
f.
Blood reaches small intestine, supplies oxygen and nutrients, picks
up nutrients
g.
Nutrient-rich venous blood leaves the small intestine and travels
via the portal vein to the liver
h.
At the kidney, waste products, nutrient excesses, and water are
removed into urine
B.
Lymphatic System
1.
Absorption of fat-soluble nutrients
a.
Long-chain fatty acids
b.
Fat-soluble vitamins
c.
Large particles that escape from bloodstream
2.
Flow of lymphatic system
a.
Lacteals within villi transport nutrients to large lymphatic vessels
b.
Lymphatic vessels merge with circulatory system through thoracic
duct at left subclavian vein
4.7
Moving through the GI Tract: Large Intestine
A.
General
1.
B.
Small intestine empties into large intestine through ileocecal sphincter (or
valve)
2.
Normally, only water, some minerals, and undigested food fibers and
starches remain
3.
Sections of large intestine (see Figure 4-20)
a.
Cecum
b.
Ascending colon
c.
Transverse colon
d.
Descending colon
e.
Sigmoid colon
4.
3 main functions
a.
Houses bacterial flora
b.
Absorbs water and electrolytes
c.
Forms and expels feces
Bacterial Flora
1.
100 trillion bacterial cells reside in colon (10x number of human cells in
body)
2.
Balance between beneficial and pathogenic bacteria may be disrupted by:
a.
Antibiotics
b.
Radiation therapy
c.
Surgery
d.
Diseases
3.
Roles of beneficial bacteria
a.
Vitamin K synthesis
b.
Biotin synthesis
c.
Lactose digestion
d.
Fermentation of fibers and starches generates short-chain fatty
acids used as energy source by colonic cells
4.
Ileocecal valve prevents migration of bacteria into small intestine
5.
Probiotics and Prebiotics
a.
Probiotics
i.
Live microorganisms that provide health benefits
ii.
Sources include yogurt, miso, supplements
iii.
Examples include lactobacilli and bifidobacteria
iv.
May be used to prevent and/or treat diarrhea, food allergies,
colon cancer, IBS, and inflammatory bowel disease
b.
Prebiotics
i.
Non-digestible carbohydrates that are fermented by and
promote growth of beneficial bacteria in the large intestine
ii.
6.
7.
4.8
Examples include inulin (found in chicory, wheat, onions,
garlic, asparagus, bananas), fructans, and resistant starch
(found in while grains and some fruits)
iii.
Fermentation produces short-chain fatty acids and other
organic acids
iv.
May lead to flatulence, bloating, and other GI distress
Absorption of Water and Electrolytes
a.
Of 10 l/d of water received by the GI tract, only 1% is excreted in
feces
b.
First half of the large intestine is the major site of sodium and
potassium absorption
Defecation of Feces
a.
12 - 24 hours from ingestion of meal
b.
Peristaltic waves generate mass movements, push feces toward
rectum
c.
Presence of feces in rectum stimulates defecation
d.
Internal sphincter is relaxed
e.
External sphincter is under voluntary control
f.
Composition: 75% water, 25% solids (indigestible plant fibers,
tough connective tissue from animal foods, bacterial cells)
When Digestive Processes Go Awry
A.
Heartburn and Gastroesophageal Reflux Disease
1.
Half of US adults occasionally experience heartburn (a.k.a. acid
indigestion)
2.
Occurs when stomach acid backs up into the esophagus, most often after a
large or high-fat meal
3.
Experiencing heartburn 2x/week may signal gastroesophageal reflux
disease (GERD)
4.
Symptoms of GERD may include
a.
Heartburn
b.
Hoarseness
c.
Swallowing difficulty
d.
Coughing
e.
Gagging
f.
Nausea
5.
Severe effects of GERD may include
a.
Weight loss
b.
Ulceration
c.
Bleeding
6.
7.
B.
d.
Anemia
e.
Increased risk of esophageal cancer
Potential causes of GERD
a.
Immature digestive tract (infants, children)
b.
Hiatal hernia: protrusion of stomach through diaphragm into chest
cavity
c.
Alcohol use
d.
Overweight
e.
Smoking
f.
Pregnancy
g.
Certain foods (chocolate, caffeine, citrus fruits, fatty fried foods,
garlic, onion, spicy foods, tomato-based foods)
Treatment for GERD
a.
Small frequent meals
b.
Avoidance of offending foods
c.
Delay of laying down after eating
d.
Weight loss
e.
Smoking cessation
f.
Limiting alcohol intake
g.
Medications
i.
Antacids
ii.
H2 blockers
iii.
Proton pump inhibitors
h.
Surgery to strengthen LES
Ulcers
1.
Small erosion in top layer of cells in stomach or duodenum
2.
Potential causes
a.
Helicobacter pylori infection weakens mucus barrier that protects
the GI tract
b.
Excessive aspirin or other NSAID use suppress prostaglandin
synthesis, weakening mucus barrier
c.
Alcohol use
d.
Smoking
e.
Disorders than increase stomach acid production
3.
Symptoms
a.
Gnawing or burning pain in the stomach region between meals or
overnight; often relieved by eating or antacids
b.
Nausea/vomiting
c.
Loss of appetite
d.
Weight loss
4.
C.
Complications
a.
Bleeding, leading to anemia and fatigue
b.
Perforation, leading to infection
5.
Treatment
a.
“Sippy diet” is now known to worsen ulcers because calcium
stimulates acid secretion
b.
Antibiotic treatment for H. pylori infection
c.
H2 blockers, proton pump inhibitors
d.
Bismuth subsalicylate
e.
Smoking cessation
f.
Limiting NSAID use
g.
Avoidance of irritating foods
Gallstones
1.
Affect 10 - 20% of US adults
2.
Cholesterol and bile pigments in bile form crystal-like particles
3.
Related to slow gallbladder motility and bile composition (too little bile,
too little phospholipids, too much cholesterol)
4.
Factors that increase risk for gallstones
a.
High-calorie, low-fiber diets
b.
Prolonged fasting
c.
Obesity
d.
Rapid weight loss (>3 lbs/week)
e.
Type 2 diabetes
f.
High blood lipids
g.
Sedentary lifestyle
h.
Medications (e.g., estrogen replacement therapy, birth control
pills)
i.
Female gender
j.
Pregnancy
k.
Increasing age
l.
Family history of gallstones
m.
Ethnicity (e.g., Native American, Mexican-American)
5.
Prevention of gallstones
a.
Maintenance of healthy weight
b.
Avoiding rapid weight loss
c.
Choosing plant instead of animal protein
d.
Eating high-fiber diet
e.
Using unsaturated fats
f.
Regular physical activity
6.
Symptoms (attacks occur when bile duct is blocked)
D.
E.
F.
a.
Many with gallstones are asymptomatic
b.
Intermittent pain in right upper abdomen
c.
Pain between shoulder blades or near right shoulder
d.
Nausea
e.
Vomiting
f.
Gas
g.
Bloating
7.
Treatment of gallstones
a.
Surgical removal of gallbladder
Food Intolerances
1.
Inability to digest certain food components (e.g., due to low enzymes)
2.
Usually requires large amounts of offending foods
3.
Food intolerances ≠ food allergies
4.
Symptoms vary widely
5.
Common causes
a.
Digestive enzyme deficiency (e.g., lactase)
b.
Sensitivity to food components (e.g., gluten)
c.
Synthetic compounds (e.g., coloring agents, sulfites, MSG)
d.
Medication and chemical residues in production of livestock and
crops
e.
Toxic contaminants (e.g., mold, bacteria)
Intestinal Gas (flatulence)
1.
Humans produce 1 - 4 pints/d, pass gas ~14 x/d
2.
Flatulence is composed of carbon dioxide, oxygen, nitrogen, hydrogen,
methane, and small amounts of sulfur-containing gas
3.
Sources
a.
Swallowed air
b.
Fermentation of undigested carbohydrates by colonic bacteria
4.
Treatment
a.
Beano
b.
Lactase
c.
Eating fewer gas-forming foods
Constipation
1.
Difficult or infrequent (<3x/week) bowel movements caused by slow
movement of fecal material through the large intestine
2.
Increases with age because of slowed gastric motility
3.
Causes
a.
Ignoring urge to defecate
b.
Complications of diabetes
c.
Irritable bowel syndrome
d.
e.
f.
G.
Depression
Pregnancy
Medications (e.g., antacids, antidepressants, calcium and iron
supplements)
g.
Low-fiber diet
4.
Treatment
a.
High-fiber diet (25 - 35 g/d) including whole grains, beans, fruits,
vegetables)
b.
Increased fluid intake
c.
Develop more regular bowel habits
d.
Relaxation and daily exercise
e.
Laxatives (short term only)
i.
Bulk-forming laxatives (safest)
ii.
Osmotic laxatives
iii.
Stimulant laxatives
iv.
Stool softeners
v.
Lubricant laxatives (not recommended due to decreased
absorption of fat-soluble vitamins)
vi.
Enema: insertion of fluid into rectum and colon
(infrequently prescribed, little evidence of benefit)
Diarrhea
1.
Loose, watery stools occurring more than 3x/d
2.
Causes
a.
Bacterial or viral infection
b.
Parasites
c.
Food intolerances
d.
Medications (e.g., magnesium-containing antacids, some
antibiotics)
e.
Intestinal diseases
f.
IBS
g.
Excessive consumption of poorly absorbed substances (e.g.,
sorbitol)
3.
Treatment
a.
Fluid and electrolyte replacement
b.
Normal diet, but avoid greasy, high-fiber, and very sweet foods
4.
Requires prompt treatment
a.
In children
i.
<6 months of age
ii.
Blood in the stool
iii.
Frequent vomiting
iv.
v.
H.
I.
High fever
Signs of dehydration
b.
In adults
i.
Lasts >3 d
ii.
Fever
iii.
Blood in stool
iv.
Severe abdominal pain
Irritable Bowel Syndrome
1.
Affects 10 - 15% of US population; more common among women than
men
2.
Symptoms
a.
Irregular bowel function, probably due to abnormal intestinal
motility
b.
Abdominal pain, probably due to decreased threshold for
abdominal distension
c.
Abdominal distension
3.
Does not increase risk for serious digestive problems or cancer
4.
Suspected causative factors
a.
Stress
b.
Dietary intolerances
5.
Treatment
a.
Increased dietary fiber
b.
Consumption of probiotics
c.
Restriction of offending foods (high-fat foods, dairy products,
wheat, citrus, caffeine, corn, legumes, gas-forming fruits and
vegetables)
d.
Consuming low-fat, frequent meals
e.
Stress reduction
f.
Psychological counseling
g.
Antidepressant medications
h.
Peppermint oil and ginger
Hemorrhoids (piles)
1.
Affects ~half of adults over age 50
2.
Swollen veins of rectum and anus
3.
Common causes
a.
Obesity
b.
Prolonged sitting
c.
Violent coughing or sneezing
d.
Pregnancy
e.
Straining during bowel movements
4.
5.
4.9
f.
Low-fiber diet
g.
Heredity
Symptoms
a.
Pain
b.
Itching
c.
Bleeding (may indicate more serious problems, should lead to
physician consultation)
d.
Sensation of incomplete elimination
Treatment
a.
Application of warm, soft compresses or sitting in tub of warm
water for 15 - 20 minutes
b.
Daily exercise
c.
Adequate fiber intake
d.
Preparation H
e.
Surgical treatment
Expert Perspective: Celiac Disease
A.
Immune-related disorder caused by physiological response to gluten (found in
wheat, rye, barley, spelt, triticale)
1.
Gluten proteins damage intestinal cells, causing villi to flatten, resulting in
malabsorption of nutrients
2.
Affects 1 in 133 people
3.
More people may be sensitive to gluten, benefit from gluten-free diets
B.
Physiological effects
1.
Intestinal gas
2.
Bloating
3.
Diarrhea
4.
Constipation
5.
Abdominal pain
6.
Weight loss or gain
7.
Anemia
8.
Bone disease
9.
Autoimmune disease
10.
Fatigue
11.
Slow growth in children
12.
Ataxia (impaired coordination) and other neurological conditions
13.
Dermatitis herpetiformis
14.
Infertility
C.
Treatment
1.
Drug therapies are under research
2.
3.
Gluten-free diet (limits grain choices)
a.
May include corn, rice, buckwheat
b.
Food labels now identify gluten in products
c.
Crohn’s disease and colitis should be ruled out by a physician
d.
Blood tests and intestinal biopsies can diagnose celiac disease
Long-term complications
a.
Weight loss
b.
Diarrhea
c.
Anemia
d.
Headaches
e.
Muscle pain
f.
Increased risk of GI tract cancers
g.
Malnutrition