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 
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       Nutrition & Diet Therapy (7  Edition)
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       Nutrition & Diet Therapy (7  Edition)
                   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
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       Nutrition & Diet Therapy (7  Edition)
         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
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       Nutrition & Diet Therapy (7  Edition)
         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
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       Nutrition & Diet Therapy (7  Edition)