Chapter 24
CHAPTER 24 – NUTRITION AND LOWER GASTROINTESTINAL DISORDERS
CHAPTER SUMMARY
Common lower gastrointestinal symptoms and complications with nutrition implications include
constipation, intestinal gas, diarrhea, bacterial overgrowth and steatorrhea. Causes of constipation
include low fiber intake, physical inactivity and overall low food intake; all of which can be reversed to
treat the condition, and various systemic disorders, neurological conditions, psychological problems and
side effects of several classes of medications. Although many individuals may self-diagnose themselves
as having intestinal gas, it may actually be dyspepsia or irritable bowel syndrome. Diarrhea can have
many causes and may be acute or chronic. Treatment of diarrhea is essential to prevent dehydration and
electrolyte imbalances. Bacterial overgrowth can be caused by gastric surgery, conditions that slow
intestinal motility, and reduced gastric acid secretion. Treatment includes antibiotics, cessation of acidreducing therapies, use of medium-chain-triglycerides (MCT) and dietary supplements. Steatorrhea, fat
maldigestion or malabsorption, can be caused by pancreatitis, cystic fibrosis, Crohn’s disease, and celiac
disease. Consequences of fat malabsorption include weight loss and malnutrition, essential fatty acid
deficiency, increased risk of bone loss and increased risk of oxalate stone formation. Treatment for
steatorrhea may include a fat-restricted diet and the incorporation of MCT oil.
Malabsorption syndromes can have significant nutrition consequences. Common malabsorption
syndromes include pancreatitis, cystic fibrosis, celiac disease, inflammatory bowel disease and short
bowel syndrome. Pancreatitis, inflammation of the pancreas, can be acute or chronic, with excessive
alcohol consumption being the primary cause for both conditions. Chronic pancreatitis can cause
irreversible damage to pancreatic tissue. Medical nutrition therapy for acute pancreatitis includes a
gradual progression from NPO status to solid foods in small, frequent feedings, typically starting with a
low-fat diet. Medical nutrition therapy for chronic pancreatitis includes abstinence from alcohol, dietary
supplements, pancreatic enzyme replacement and a low-fat diet as needed. Cystic fibrosis, an inherited
mutation in the gene for a membrane protein that transports chloride ions, can result in serious
complications involving the lungs and pancreas. Medical nutrition therapy for cystic fibrosis includes
high energy intake, vitamin and mineral supplements, pancreatic enzyme replacement therapy, liquid
dietary supplements, and often supplemental tube feedings. Celiac disease, an abnormal response to a
protein fraction in wheat gluten, gliadin, involves treatment with a lifelong gluten-free diet, eliminating
all foods that contain wheat, rye, barley and possibly oats. Inflammatory bowel disease, including
Crohn’s disease and ulcerative colitis, involves careful nutrition planning to replace lost nutrients and
correct nutrient deficiencies. Short bowel syndrome, the malabsorption syndrome that results when the
absorptive capacity of the remaining intestine is insufficient for meeting nutritional needs, can be helped
by intestinal adaptation. Medical nutrition therapy for short bowel syndrome includes appropriate
rehydration, gradual progression of oral feedings and total parenteral nutrition after surgery. Dietary
recommendations include low lactose intake, fluids between meals, emphasis on complex carbohydrates,
low oxalate intake and vitamin and mineral supplementation.
Conditions affecting the large intestine with nutrition implications include irritable bowel syndrome,
diverticular disease of the colon and ostomies. Irritable bowel syndrome includes chronic and recurring
intestinal symptoms that cannot be explained by specific physical abnormalities, but stress and anxiety
are among the contributing factors. Dietary treatment includes a high-fiber diet and avoidance of lactose
in lactose-intolerant individuals. High-fiber diets are also beneficial for the treatment of diverticulosis, the
presence of small pouches (diverticula) in the intestinal wall. Treatment for medical conditions that affect
the large intestine sometimes requires surgical removal of some or all of the large intestine. Patients with
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Chapter 24
ostomies, including colostomies and ileostomies, may experience diarrhea, excessive fluid loss and
obstructions. Dietary intervention includes chewing thoroughly, adequate fluid intake and avoiding
foods that may cause excessive gas production.
Highlight 24 reviews food allergy diagnosis and dietary concerns.
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