Medical Nutrition Therapy for Lower Gastrointestinal Tract

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Medical Nutrition Therapy for Lower
Gastrointestinal Tract DisordersChapter 30NFSC
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Chapter Outline

• Common Intestinal Problems
• Diseases of the Small Intestine
• Intestinal Brush-Border Enzyme Deficiencies
• Inflammatory Bowel Diseases
• Disorders of the Large Intestine
• Intestinal Surgery

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Common Intestinal Problems
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Intestinal Gas Flatulence

• Pathophysiology
• Intestinal gases N2, O2, CO2, H2, CH4
• 200ml of gas normally present in GI tract
• Humans excrete 700 ml/d
• May be swallowed or produced within the GI tract
• May be absorbed into the bloodstream and exit
  through the lungs, eructation (belching), or
  rectally.

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Intestinal Gas Flatulence

• Flatulence ?volume or frequency of passage of
  gas. Abdominal distention or cramping pain
• Causes Inactivity, ?GI motility, aerophagia,
  dietary components, GI disorders.
• Rectal gas high in N2 O2 aerophagia.

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Intestinal Gas Flatulence

• Bacterial fermentation
• ??Gas in stomach small intestine.
• Colon ?H2 CO2 ( CH4) ?fecal pH
• Indicates XS colonic bacterial fermentation
• Suggests malabsorption of a fermentable
  substrate.
• ?dietary fiber, resistant starches, lactose if
  lactase deficient
• ??Fructose, sugar alcohols, or sucrose consumption

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Intestinal Gas Flatulence

• MNT
• Eat slowly, chew with mouth closed, refrain from
  drinking through straws.
• ?CHOs likely to be malabsorbed and fermented
• Legumes, soluble fiber, resistant starches,
  simple sugars.
• Undigested CHOs in colon ? fermented to
  short-chain F.A.s gases.
• Legumes stachyose raffinose only partially
  digested in small intestine.
• Dose of CHO starches in ?quantities may leave a
  large portion undigested for bacterial action

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Causes of Constipation
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Medical Treatment for Children

• Most severe cases flaccid colon, insensitive to
  distention
• Initial treatment laxatives lubricants
• Then fiber intake

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MNT for Constipation

• Adequate soluble insoluble fiber 2L water/d
• Fiber
• ?Colonic fecal fluid
• ?Microbial mass
• ?Stool weight frequency
• ?Rate of colonic transit.
• Softens stools makes them easier to pass

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MNT for Constipation

• Recommended amount of fiber 14g/1000kcal.
• Women 25g/d
• Men 38g/d
• Best whole grains, fruits, vegetables, legumes,
  seeds, nuts.
• Brans powdered fiber supplements when intake
  not sufficient

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Diarrhea Pathophysiology

• Excessively rapid transit
• ?Enzymatic digestion
• ?Absorption of fluids nutrients
• ?Secretion of fluids into GI tract

• Causes
• Inflammatory disease
• Fungal, bacterial or viral infections
• Medications
• Overconsumption of sugars
• Insufficient/damaged mucosal surface
• Malnutrition

• Frequent evacuation of liquid stools, gt300 ml
• Excessive loss of fluid electrolytes, esp. Na
  K

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Diarrhea Pathophysiology

• Osmotic diarrhea poorly absorbed osmotically
  active solutes in intestinal tract
• Dumping syndrome, lactose ingestion in lactase
  deficiency.
• Secretory diarrhea active secretion of
  electrolytes water by intestinal epithelium.
• Bacterial exotoxins, viruses, ?intestinal hormone
  secretion.
• Exudative diarrhea mucosal damage ? outpouring
  of mucus, fluid, blood, plasma proteins,
  electrolytes and water in the gut.
• Crohns disease, ulcerative colitis, radiation
  enteritis.

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Diarrhea

• Medical Treatment
• Identify treat underlying problem
• Fluid electrolyte replacement
• Oral glucose electrolyte solutions with added K
• Parenteral feeding may be required

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Diarrhea

• MNT
• Broths electrolyte solutions
• Minimum-residue diet
• Modest amounts of fat if lipid digestive
  mechanisms are intact
• Sugar alcohols, lactose, fructose, ?sucrose may
  worsen osmotic diarrhea

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Diarrhea MNT

• SCFAs substrates for colonocytes
• Facilitate absorption of fluid and salts
• May help regulate GI motility
• Probiotics sources of bacteria to reestablish
  beneficial gut flora.
• Prebiotics
• Favor friendly lactobacillus and bifidus
  microbes.
• Slow gastric emptying
• Hold water

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Diarrhea MNT

• Early refeeding needed to restore the
  compromised GI tract
• ?Stool output and shortens the duration of
  illness.
• Micronutrient replacement accelerates
  regereneration of mucosal cells
• Even during acute diarrhea, gut absorbs 60 of
  food eaten. Resting the gut is actually more
  damaging.

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Diarrhea MNT

• MNT for infants children
• Aggressive immediate fluid electrolyte
  replacement
• Standard oral rehydration solutions 2 glucose
  45-90mEq/L of Na, 20 mEq/L of K, and a citrate
  base
• Liquid or semisolid diet continuously during
  bouts of acute diarrhea.
• ? Maintain adequate intake

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Steatorrhea Pathophysiology

• Causes
• Liver disease/biliary obstruction ? Inadequate
  bile secretion
• Blind loop syndrome
• Bacterial overgrowth ? anatomical alterations of
  small intestine (a loop disconnected from the
  main tract) ? malabsorption
• Pancreatic insufficiency
• Inadequate reabsorption of bile salts
• Sprue, Crohns disease, GI irritation

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Steatorrhea Pathophysiology

• Normally 90-98 of fat is absorbed
• Steatorrhea up to 20 of fat remains in stool
• Medical Treatment
• Treat the underlying cause
• Pancreatic insufficiency oral pancreatic enzymes

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Steatorrhea MNT

• Chronic Wt loss ? ?E intake (protein complex
  CHO)
• Medium-chain triglycerides (MCTs)
• Short chain length ? easier absorption without
  bile acids
• MCTs and SCTs enter the portal venous blood ?
  directly to the liver
• Available in enteral formulas as MCT oil
  (incorporated into foods), doses /15g/feeding
• Vitamin deficiencies (fat-soluble) and Ca, Zn, Mg

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Diseases of the Small Intestine
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Celiac Disease (Gluten-Sensitive Enteropathy or
Nontropical Sprue)
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Celiac Disease

• MNT
• Complete withdrawal of gluten from diet
• Omit all dietary wheat, rye, and barley oats
  under investigation
• Deficiencies supplement with vitamins, minerals,
  extra protein
• Anemia Fe, folate, B12
• Osteoporosis/osteomalacia Ca vit. D
• Steatorrhea Vit. A E
• Purpura, bleeding, prolonged prothrombin time
  vit. K
• Severe diarrhea Electolyte fluid replacement
• MCT to provide calories if steatorrhea

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Tropical Sprue

• Pathophysiology
• Infectious diarrhea occurring in tropical areas
• Organism may differ from one region to another
• Shortened intestinal villi
• Atrophied inflamed gastric mucosa, ?HCl
  intrinsic factor secretion
• Symptoms
• Diarrhea, anorexia, abdominal distention
• Nutritional deficiencies night blindness,
  glossitis, stomatitis, cheilosis, pallor, edema.
• Anemia Fe, folic acid, B12 deficiencies

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Glossitis
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Cheilosis
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Purpura
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Stomatitis
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Tropical Sprue

• MNT
• Restore fluids, electrolytes, nutrients
• Folate therapy 5mg/d orally
• Intramuscular vit. B121000mg/month
• Correct related anemias
• Broad-spectrum antibiotics

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Intestinal Brush-Border Enzyme Deficiencies
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Lactose Maldigestion Lactose Intolerance

• Pathophysiology
• Lactase deficiency 70 of adults worldwide
• Most common CHO intolerance
• Nonhydrolyzed lactose passes into the colon
• ? fermented by bacteria
• ? SCFAs gases, CO2, H2
• ? bloating, flatulence, cramps
• Lactose acts osmotically ?fecal water, loose
  stools or diarrhea

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Lactose Maldigestion Lactose Intolerance

• Diagnosis
• History of GI symptoms after milk ingestion
• Abnormal hydrogen levels in the breath
• H2 produced in the colon, absorbed in the
  bloodstream, exhaled in the lungs

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Lactose Intolerance MNT

• ?Consumption of lactose containing foods
• Ca supplements
• Up to 6-12g lactose can be tolerated
• When taken with meals
• In the form of cheeses or cultured dairy products
• Incremental exposure to fermentable sugar (e.g.
  lactulose) ? ? tolerance
• By altering colonic flora

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Lactose Intolerance - MNT

• Tolerance to yogurt
• Microbial ?-galactosidase facilitates lactose
  digestion
• Sensitive to freezing ? frozen yogurt not as well
  tolerated
• Lactase enzyme milk products treated with lactase

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Inflammatory Bowel Diseases

• 2 major forms
• Crohns disease
• Ulcerative colitis

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Ulcerative Colitis
Crohns Disease

• Small large intestine
• Segmental (skip areas)

• Starts in rectum
• Progresses in a retrograde fashion to colon

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Pathophysiology Algorithm Inflammatory Bowel
Disease
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IBD - MNT

• Energy needs not ?, unless wt gain is desired
• Protein requirements may ?50
• Supplemental vitamins and minerals when
• Maldigestion, malabsorption, drug-nutrient
  interactions
• Patient cannot eat a complete diet
• Diarrhea can aggravate losses of Zn, K, Se

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IBD MNT

• Minimal-residue diet
• ?? poorly absorbed, hyperosmolar sugars,
  caffeine, fiber
• ? ?Microbial populations in the colon
• Fat malabsorption
• ? Supplementation with foods made with MCT

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IBD MNT

• Dietary factors that cause IBD
• Increased sucrose intake
• Lack of fruits vegetables
• Low intake of dietary fiber
• Altered omega-6/3 fatty acid ratios
• Specific food allergies

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Disorders of the Large Intestine
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Irritable Bowel Syndrome

• Pathophysiology
• Altered intestinal motility
• May involve more than the large intestine
• No obvious tissue damage, inflammation, or
  immunologic involvement

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Heightened Gastrointestinal Response to Enteric
Stimuli
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Irritable Bowel Syndrome

• 3 predominant symptom patterns diarrhea,
  constipation, abdominal pain
• Other symptoms
• Abdominal pain (typically relieved by defecation)
• Bloating, excessive flatulence
• Sensation of incomplete evacuation, rectal pain,
  mucus in the stool

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Irritable Bowel Syndrome

• Onset between adolescence age 40
• Factors that may worsen symptoms
• XS use of laxatives other over-the-counter
  medications
• Antibiotics
• Caffeine
• Previous GI illness
• Lack of regularity in sleep, rest, fluid intake
• Hypersensitivity to certain foods

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IBS Treatment

• Medical management
• Medications
• Antispasmodic, anticholinergic, antidiarrheal,
  prokinetic, antidepressive agents
• relaxation, stress reduction

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IBS MNT

• Patients may overrestrict diet ? Ensure adequate
  nutrient intake
• Less well tolerated than in normal persons
• XS dietary fat, caffeine, sugars (lactose,
  fructose, sorbitol)
• Large meals, alcohol
• Bran
• 25g/day to normalize bowel habit
• Insufficient fiber from food sources ? bulk
  laxatives
• Adequate fluid especially when powdered fiber
  supplements are used
• Prebiotic foods
• Maintenance of healthy microflora
• Resistance to pathogenic infections

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Diverticular Disease

• Complications
• Painless, mild bleeding, altered bowel habits
• Diverticulitis
• Inflammation, abscess formation, acute
  perforation, acute bleeding, obstruction, sepsis
• May require surgery

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Mechanisms by which low-fiber, low-bulk diets
might generate diverticula
Colon contents are bulky ? muscular contractions
exert pressure longitudinally
Fecal contents small in diameter ? contractions
produce occlusion exert pressure against the
colon wall ? diverticular hernia
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Diverticular Disease

• MNT
• High-fiber diet
• ? Soft, bulky stools ? lower intracolonic
  pressures
• Exercise helps in both constipation
  diverticular disease
• ?Fiber intake gradually (may cause bloating or
  gas)
• Adequate fluid intake
• Acute flare-up of diverticulitis
• Low-residue diet, elemental diet, or TPN,
  followed by a gradual return to high-fiber diet
• Fat intensifies colonic smooth-muscle
  contractions ? Low-fat diet
• Avoid very coarse materials (e.g. husks
  surrounding sunflower seeds)

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As the feces move from the ileocecal valve to the
anus, water is absorbed and the feces become more
solid.