Chapter 18 book notes Flashcards
A diagnosis of constipation is based, in part, on a defecation frequency of fewer than
-three bowel movements per week
The prevalence of constipation is higher in ?? than in ?? and is especially
high in older adults (??years and older).
-women than in men
-65
The risk of constipation is increased in individuals with a
-low-fiber diet, low food intake, inadequate fluid intake, or low level of physical activity.
Medical conditions often associated with constipation include:
-diabetes mellitus and hypothyroidism
Neurological conditions such as ?? disease, ??? ,
and ??? may cause motor problems that lead to constipation.
-Parkinson’s disease
-spinal cord injury
-multiple sclerosis
In individuals with a low fiber intake,
the initial treatment for constipation is a gradual increase in fiber
intake to at least ?? to ?? `grams per day
-20 to 30
High-fiber diets increase ??? and ??? content
and promote a more rapid transit of materials through the colon
-stool weight and fecal water
The transition to a high-fiber diet may be difficult for some people because it can increase intestinal ???
-gas
-so the transition should be gradual
Fiber supplements can also be used to help constipation such as:
-methylcellulose
-psyllium
-polycarboyphil
Which fiber supplements do not increase intestinal gas?
-methylcellulose and polycarbophil
Consuming ?? or ??juice is often recommended because
they contain compounds that have a mild laxative effect
-prunes or prune juice
Skipping breakfast is discouraged, as ??? is highest after a morning meal
-colonic motility
Structural/ functional abnormalities that inhibit elimination:
-slow colonic transit
-altered pelvic or anal functioning
For patients with severe constipation who do
not respond to dietary or laxative treatments, physicians may prescribe
medications called:
-prokinetic agents that stimulate colonic contractions
flatulence:
-the condition of having excessive intestinal gas, which causes abdominal discomfort.
dietary fibers are not ?? , they pass into the colon and are fermented by ?? , which produce ?? as a by-product
-digested
-fermented
-gas
Other incompletely digested or poorly absorbed carbohydrates have similar effects; these include:
-indigestible carbohydrates in beans (raffinose and stachyose)
-lactose
-fructose
-some sugar alcohols (sorbitol, xylitol, mannitol)
FODMAPs:
What kind of FODMAP diet will help reduce flatulence and diarrhea
-an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, which are incompletely
digested or poorly absorbed carbohydrates that are fermented in the large intestine;
-a low-FODMAP diet may help to reduce flatulence, abdominal distention, and diarrhea
Carbonated beverages contain dissolved ??? gas, which
contributes to intestinal gas
-carbon dioxide
Diarrhea is characterized by the passage of ?? . In most cases, it lasts for only
-frequent, watery stools
-a day or two and subsides without complication.
Severe or persistent diarrhea, however, can cause
-dehydration and electrolyte imbalances.
Diarrhea is a complication of multiple GI disorders and may also be
caused by
-GI infections,
-medications,
-dietary substances
osmotic diarrhea and common causes
-a type of diarrhea that occurs when the intestines do not absorb enough fluids or electrolytes due to the presence of poorly absorbed solutes
-common causes include: high intakes of poorly absorbed sugars, lactase deficiency, and indigestion of laxatives that contain magnesium or phosphates
secretory diarrhea and common causes
-fluid secreted by the intestines exceeds the amount that can be reabsorbed by intestinal cells.
-foodborne illness, intestinal inflammation and various chemical substances
Motility disorders that cause rapid intestinal transit may also result in ?? because they reduce
-diarrhea
-the contact time available for fluid reabsorption
medical treatment of diarrhea
-antibiotics are prescribed to treat intestinal infections
-If a medication is the cause of diarrhea, a different drug may be prescribed.
-If certain foods are responsible, they can be omitted from the diet.
People with severe, intractable diarrhea sometimes require
-total parenteral nutrition.
the presence of glucose in the solution
enhances
-sodium and water absorption.
Oral rehydration solutions can be purchased or easily mixed using
-water, salts, and a source of glucose
Sports drinks and oral rehydration therapy:
-not ideal fluids for rehydration because their sodium content is too low, but they can be used if accompanied by salty snack foods.
The dietary treatment initially recommended is often a
-low-fiber, low-fat, lactose-free diet
?? and??? , which are poorly absorbed, retain fluids in the colon and contribute to osmotic diarrhea.
-fructose and sugar alcohols
dairy products may worsen ??? diarrhea in persons who are lactose intolerant
-osmotic
patients should avoid caffeinated coffee and tea
because caffeine
-stimulates GI motility and can thereby reduce water reabsorption.
What pectin sources can be added to foods or baby formulas to help thicken stool consistency?
-apple powder and banana flakes
foods that may worsen diarrhea:
-high fiber foods
-indigestible carbohydrates
-fructose or sugar alcohols
-dairy products (especially a lactose intolerant person)
-Gas producing foods
-caffeine
To digest and absorb nutrients, we depend on normal digestive…
-secretions and healthy intestinal mucosa
Malabsorption can therefore be caused by what disorders?
-pancreatic disorders that cause enzyme or bicarbonate deficiencies
-disorders that result in bile deficiency,
-inflammatory diseases damage intestinal tissue.
In some cases, the treatment of an intestinal disease requires surgical removal of a section (resection) of the small intestine, leaving minimal…
-absorptive capacity
Malabsorption rarely involves a
- single nutrient
When fat is malabsorbed, what is also malabsorbed?
-fat-soluble vitamins
-minerals
-food energy
Which nutrient is most frequently malabsorbed and why?
-fat
-because both digestive enzymes and bile must be present for its digestion
chronic pancreatitis and cystic fibrosis can decrease the secretion of ??, whereas severe liver disease can cause ?? insufficiency
-pancreatic lipase
-bile
Fat malabsorption can also be caused by conditions or treatments that damage the intestinal mucosa, such as
-inflammatory bowel diseases,
-AIDS,
-radiation treatments for cancer.
Fat malabsorption is often evidenced by ???
-steatorrhea
-presence of excessive fat in the stools
Elimination of more than ?? to ?? percent of the fat intake generally indicates fat malabsorption
-7 to 8
Malabsorption of some minerals, including ?? , ?? ,
and ?? , often occurs because the minerals form ?? with the unabsorbed fatty acids and bile acids.
-calcium, magnesium, and zinc
-soaps
soaps:
-chemical compounds formed from fatty acids and positively
charged minerals.
Another consequence of fat malabsorption is an increased risk of ??? , which are most often composed of calcium ?? .
-kidney stones
-oxalates
The oxalates in foods ordinarily bind to
?? in the small intestine and are eliminated in the stool.
-calcium
If calcium instead binds to fatty acids or bile acids, the oxalates are free to be absorbed into the ?? and are ultimately excreted in the ??.
-blood
-urine
If the steatorrhea does not improve, a
??-restricted diet may be recommended
-fat
Because fat is a primary energy source, it should
not be
-restricted more than necessary.
What can be used as a alternative source of dietary fat?
-medium chain triglycerides
-do not require lipase or bile for digestion and absorption
how is the small intestine protected from bacterial growth?
-gastric acid, which destroys bacteria
-peristalsis, which flushes bacteria through small intestine before multiplying
-immunoglobulins, they are secreted into the GI lumen
What happens when bacterial overgrowth does occur?
-it leads to fat malabsorption because the bacteria dismantle the bile acids that are needed for emulsifying fat.
Bacterial overgrowth leads to what vitamin deficiencies?
-A, D, and E