Nutrition & Diet Therapy (7 th Edition) Fiber-Modified Diets for Lower GI Tract Disorders Chapter...

Nutrition & Diet Therapy (7th Edition)

Fiber-Modified Diets forLower GI Tract Disorders

Chapter 18


I. Modifying Fiber Intake• Modification may require either increase or

decrease in dietary fiber; RDI is 38 g/day– Insoluble fibers: increase fecal weight & promote rapid

passage of wastes through large intestine (aka dietary fiber, found in whole grains)

– Soluble fibers: more viscous; slow passage of food– Health recommendation: most people should increase

fiber intake by increasing consumption of whole grains– Side effects of high-fiber diet: increased intestinal gas

(flatulence)—should be added gradually & portions increased as tolerance improves

Diets high in soluble fibers can lower

blood cholesterol levels


II. Disorders of Bowel Function

• Constipation– Difficulty passing stools (straining) or

infrequent bowel movements; often diagnosed when individual has fewer than 3 bowel movements/week

– Causes:• Food intake & activity-related causes: low fiber &/or

food intake, inactivity• Medical & neurological conditions: diabetes mellitus,

chronic renal failure, hypothyroidism, Parkinson’s disease, spinal cord injury, multiple sclerosis

• Pregnancy• Some medications & dietary supplements


Disorders of Bowel (cont’d)

• Constipation (con’t)– Treatment

• Gradual increase in fiber intake, especially– Wheat bran– Fruits & vegetables – Fiber supplements

• Adequate fluid intake• Foods with mild laxative effects: prunes & prune juice• Laxatives, enemas & suppositories• Medical treatment

– Medications to increase peristalsis– Surgical intervention (colon resection, colostomy) as

last resort


Disorders of Bowel (cont’d)• Diarrhea

– Passage of frequent, watery stools– Severe or persistent diarrhea can cause dehydration

& electrolyte imbalance– Causes

• Complication of medical problems• Infection, medications, dietary substances

– Treatment• Correction of underlying medical disorder• Change in medication or omission of offending

foods• Bulk-forming agents to reduce liquidity of stool• Antidiarrheal drugs for chronic diarrhea• Parenteral nutrition for severe, intractable

diarrhea


Disorders of Bowel (cont’d)• Diarrhea (con’t)

– Nutrition therapy• Depends on cause, severity & duration of

diarrhea & degree of fluid loss• Rehydration therapy: replacement of fluid &

electrolytes for severe diarrhea• Fiber restriction for some individuals• Foods & beverages containing fructose, sugar

alcohols & lactose may aggravate symptoms• Avoidance of caffeine-containing products

– Rehydration therapy• The replacement of fluids and electrolytes

(water, salts, and glucose or sucrose) if diarrhea is severe.


Disorders of Bowel (cont’d)• Irritable bowel syndrome

– Characterized by chronic, recurrent & unexplainable intestinal symptoms

– Symptoms• Both diarrhea & constipation• Flatulence, bloating, distention• Mild to severe, often interfering in routine daily activities• Individuals may eventually become asymptomatic

– Possible Causes: May be associated with colonic response to meals, GI hormones & stress

– Treatment• Dietary adjustments• Stress management & behavioral therapies• Medications for management of symptoms


Disorders of Bowel (cont’d)

• Irritable bowel syndrome (con’t)– Medical nutrition therapy

• Complete diet history to reveal behaviors that improve or worsen symptoms

• Dietary changes that help one symptom may aggravate another

• Increase fiber intake to reduce constipation & improve stool bulk

• Bulking agent• Avoidance of milk products (if lactose intolerant)• Caffeine & alcohol can exacerbate symptoms• Small, frequent meals• Possible low fat diet


III. Inflammatory Bowel Diseases (IBD)

• Crohn’s disease– Involves small intestine & may result in

nutrient malabsorption– Complications

• Can occur in any region of GI tract—usually affects ileum &/or colon

• Deep inflammation, ulcerations, fissures & fistulas• Intestinal obstruction, intestinal cancers• Malnutrition• Malabsorption of fat, fat-soluble vitamins, calcium,

magnesium, zinc• Vitamin B12 deficiency, anemia


Inflammatory Bowel Diseases (cont’d)

• Ulcerative colitis– Affects colon; always involves rectum & may

extend into additional segments of colon– Complications

• Tissue erosion or ulceration (primarily affecting mucosa & submucosa)

• Mild disease results in few complications, unless colon involved

• Weight loss, fever, weakness• Anemia• Dehydration & electrolyte imbalance• Protein loss


• In Crohn’s, the mucosa has a “cobblestone” appearance due to deep fissuring in the inflamed mucosal tissue

• In UC, the colon appears inflamed and reddened, and ulcers are visible


Treatment of InflammatoryBowel Diseases

• Drug treatment– Medications to control symptoms: reduce

inflammation & minimize complications• Antidiarrheal agents• Immunosuppressants• Anti-inflammatory drugs

– Help to achieve remission but associated with side effects (diet-drug interactions) detrimental to nutrition status


Inflammatory Bowel Diseases

• Medical Nutrition Therapy– Crohn’s disease:

aggressive dietary management

– Manage symptoms & complications

• High-kcalorie, high-protein• Liquid supplements• Restriction of fiber &

lactose• Vitamin & mineral

supplements

– Ulcerative colitis: requires little dietary adjustment

– In severe illness, manage symptoms & complications

• Restoration of fluid & electrolytes (possible intravenous replacement)

• Correct deficiencies resulting from protein & blood losses

• Low-fiber diet• Bowel rest (withhold foods)• Parenteral nutrition support


IV. Diverticular Disease of the Colon

• Diverticulosis: presence of pebble-size outpockets in intestinal wall (diverticula)– Incidence increases

with age– May remain symptom-

free until complication develops

– Increased fiber in diet (increased stool weight & bulk) may decrease development

• Diverticulitis: inflammation or infection developing around a diverticulum– Common complication of

diverticulosis– Spread of infection to

adjacent organs may result in development of fistula

– Infection may spread to peritoneal cavity (rare occurrence)

– Symptoms: persistent abdominal pain, fever, alternating constipation & diarrhea


Treatment for Diverticular Disease

• Focuses on symptom relief– Reducing pain– Alleviating constipation– Increasing fiber to prevent disease progression

• Add wheat bran to meals• Use bulk-forming agents• Some recommend avoidance of nuts, popcorn & foods

containing seeds—no evidence that this will reduce complications

– Antibiotics to treat infection– Clear liquid diet, progressed to solid foods as tolerated– Bowel rest when necessary; intravenous fluid treatment– Surgical intervention to treat complications, including

removal of colon


V. Colostomies & Ileostomies

• Ostomy: surgically created opening (stoma) in abdominal wall for elimination of dietary waste; may be permanent or temporary– Colostomy: creation of stoma from section of colon– Ileostomy: creation of stoma from section of ileum– Dietary waste collected in disposable bag affixed to skin

surrounding stoma; or interior pouch may be surgically constructed behind stoma

– Stool consistency varies according to functional capacity of remaining length of colon

• Removal of small portion of colon: stools may continue to be semi-solid

• Removal or bypass of entire colon: absorption of fluid & electrolytes reduced substantially, resulting in liquid stool


Nutrition Therapy for Ostomies

• Gradual progression of diet following surgery– Clear liquids, low in sugars, progressing to low-fiber diet as

tolerated– Small, frequent meals better tolerated initially– Addition of questionable foods slowly & one at a time

• Colostomy– Dietary concerns depend on length of colon removed– High-fiber diet to improve stool consistency & promote regularity– Removal of large segment: recommendations may be same as

ileostomy• Ileostomy

– Chew thoroughly to ensure adequate digestion & to prevent obstruction

– Avoidance of insoluble fibers—reduce intestinal transit time & may increase output

– Inclusion of at least 8 cups of liquid/day


Nutrition Therapy for Ostomies

Obstructions• A primary concern of ileostomy

patients• Cut food into small pieces,

carefully chew• Foods that may cause problems

– Corn– Celery– Coconut– Dried fruit– Grapes– Nuts & popcorn– Raw cabbage– Unpeeled apples

Reducing gas & odors• A concern for all ostomy patients• Avoid foods that are gas-

producing• Avoid foods that produce odors

– Fish– Eggs– Dried beans & peas– Onions & garlic– Asparagus & Brussels sprouts– Beer

• Avoid practices that increase gas production

– Smoking– Gum or tobacco chewing– Use of drinking straws– Eating quickly


Nutrition in Practice—Probiotics & Intestinal Health

• Shortly after birth, GI tract is colonized with wide variety of bacteria (flora)– Majority reside in colon– Populations vary within different regions of GI

tract– Benefits to health

• Degrade undigested or unabsorbed dietary carbohydrate, including fibers resistant to digestion

• Stimulate immune defenses to prevent overgrowth of pathogenic bacteria


Probiotics• Foods & supplements

supplying live, nonpathogenic bacteria in sufficient numbers to benefit health

• Resistant to destruction by stomach acid, bile, other digestive substances

• Alter intestinal environment to benefit human host

• Possible help for medical problems: - May prevent & treat some gastric & intestinal disorders

– Improve lactose digestion– Improve availability &

digestibility of various nutrients

– Alter susceptibility to food allergens & alleviate some allergy symptoms

– Help prevent or reverse infections in urethra & vagina

• Benefits to health not conclusive in research— therefore should be considered adjuncts to primary medical treatment for illness


Probiotics

• Intestinal disorders helped by probiotics– Shortened duration of diarrhea caused by

rotavirus in infants & children– Decreased incidence of traveler’s diarrhea in

tourists visiting high-risk areas– Prevent recurrence of infectious diarrhea in

hospitalized patients– Reduced incidence & duration of antibiotic-

associated diarrhea in infants & children– Reduced occurrence of pouchitis (inflammation of

surgical pouch created in patients with ileostomy or colostomy)


Probiotics• Sources of probiotic bacteria

– Foods—provided mainly by fermented foods• In U.S.—yogurt & acidophilus milk (produced using

species of Lactobacilli & Bifidobacteria)• In Europe & Asia—yogurt, milk, ice cream, oatmeal

gruel, soft drinks– Dietary supplements– Prebiotics in foods that may stimulate growth in large

intestine• Safety

– Infection in immune-compromised individuals– Lack of industry standards for probiotics in foods &

supplements

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