•Nutrition for Patients with Disorders of the Lower GI Tract and Accessory Organs
Chapter 18
•Nutrition for Patients With Disorders of the Lower GI Tract
•Ninety to 95% of nutrient absorption occurs in the first half of the small intestine
•Large intestine absorbs water and electrolytes and promotes the elimination of solid wastes
•Accessory organs—liver, gallbladder, and pancreas—play vital roles in nutrient digestion
•Nutrition therapy is used:
–To improve or control symptoms
–Replenish losses
–Promote healing
•Altered Bowel Elimination
•Constipation
–Difficult or infrequent passage of stools that are hard and dry
–Can occur secondary to irregular bowel habits, psychogenic factors, lack of activity, chronic laxative use, inadequate intake of fluid and fiber, metabolic and endocrine disorders, and bowel abnormalities (e.g., tumors, hernias, strictures)
–Certain medications cause constipation
•Altered Bowel Elimination (cont’d)
•Constipation (cont’d)
–Nutrition therapy
oConstipation is treated by treating the underlying cause
oIncreasing fiber and fluid intake effectively relieves and prevents constipation
oHigh-fiber diet
•Altered Bowel Elimination (cont’d)
•Constipation (cont’d)
–Nutrition therapy (cont’d)
oAdequate intake set for fiber is 25 g/day for women and 38 g/day for men
oCommon practice is to recommend fiber intake be gradually increased
oFiber intake should be spread throughout the day
oLifestyle changes to promote bowel regularity include drinking more fluid and increasing exercise
–Altered Bowel Elimination (cont’d)
•Diarrhea
–Characterized by more than 3 bowel movements a day of large amounts of liquid or semi-liquid stool
–Potential for dehydration, hyponatremia, hypokalemia, acid–base imbalance, and metabolic acidosis
–Chronic diarrhea can lead to malnutrition related to impaired digestion, absorption, and intake
•Altered Bowel Elimination (cont’d)
•Diarrhea (cont’d)
–Osmotic diarrhea occurs when there is an increase in particles in the intestine, which draws water in to dilute the high concentration
oCauses include maldigestion of nutrients (e.g., lactose intolerance), excessive intake of sorbitol or fructose, dumping syndrome, tube feedings, and some laxatives
oCured by treating the underlying cause
•Altered Bowel Elimination (cont’d)
•Diarrhea (cont’d)
–Secretory diarrhea
oRelated to an excessive secretion of fluid and electrolytes into the intestines
oCaused by infections, some medications, some GI disorders, and an excessive amount of bile acids or unabsorbed fatty acids in the colon
oTreatment
Antibiotics if cause is infectious
Symptoms may be treated with medications that decrease GI motility or thicken the consistency of stools
oAltered Bowel Elimination (cont’d)
•Nutrition therapy
–Primary nutritional concern with diarrhea is maintaining or restoring fluid and electrolyte balance
–Mild diarrhea lasting 24 to 48 hours:
oUsually requires no nutrition intervention other than encouraging a liberal fluid intake to replace losses
oHigh-potassium foods are encouraged; clear liquids are avoided because they have high osmolality related to their high sugar content, which may promote osmotic diarrhea
•Altered Bowel Elimination (cont’d)
•Nutrition therapy (cont’d)
–For more serious cases, commercial (e.g., Pedialyte, Rehydralyte) or homemade oral rehydration solutions, or IV therapy, is used to replace fluid and electrolytes
–May improve by avoiding foods that stimulate GI motility
–A low-fiber diet that is also low in fat and lactose may help decrease bowel stimulation
•Question
•One cause of osmotic diarrhea is:
a. Antibiotics
b. Maldigestion
c. Some GI disorders
d. Unabsorbed fatty acids
•Answer
b. Maldigestion
Rationale: The causes of osmotic diarrhea include maldigestion of nutrients (e.g., lactose intolerance), excessive intake of sorbitol or fructose, dumping syndrome, tube feedings, and some laxatives. It is cured by treating the underlying cause.
•Malabsorption Disorders
•Occurs secondary to nutrient maldigestion or from alterations to the absorptive surface of the intestinal mucosa
•Malabsorption related to maldigestion involves one or few nutrients
•Malabsorption that stems from an altered mucosa is more generalized, resulting in multiple nutrient deficiencies and weight loss
•Symptoms vary with the underlying disorder
•Malabsorption Disorders (cont’d)
•Excretion of fat in the stool means that essential fatty acids, fat-soluble vitamins, calcium, and magnesium are also lost through the stool
•Can cause metabolic complications
•Malabsorption Disorders (cont’d)
•Goal of nutrition therapy for malabsorption syndromes is to:
–Control steatorrhea
–Promote normal bowel elimination
–Restore optimal nutritional status
–Promote healing, when applicable
•Individualized according to symptoms and complications
•Malabsorption Disorders (cont’d)
•Lactose intolerance
–Occurs when the level of lactase is absent or deficient
–Lactose digestion is impaired
–Undigested lactose increase the osmolality of the intestinal contents
–May lead to osmotic diarrhea
•Malabsorption Disorders (cont’d)
•Lactose intolerance (cont’d)
–Lactose is fermented in the colon
–Produces bloating, cramping, and flatulence
•Malabsorption Disorders (cont’d)
•Primary lactose intolerance occurs in “well” people who simply do not secrete adequate lactase
–Least common in people of northern European descent
–May be asymptomatic when doses less than 4 to 12 g of lactose are consumed (e.g., ⅓ to 1 cup of milk) or when lactose is consumed as part of a meal
–Chocolate milk is usually better tolerated than plain milk
•Malabsorption Disorders (cont’d)
•Primary lactose intolerance (cont’d)
–Know individual limits
–Lactose-reduced milk and lactase enzyme tablets or liquid may be used
•Malabsorption Disorders (cont’d)
•Lactose intolerance secondary to gastrointestinal disorders that alter the integrity and function of intestinal villi cells, where lactase is secreted
–Loss of lactase may also develop secondary to malnutrition because the rapidly growing intestinal cells that produce lactase are reduced in number and function
–Tends to be more severe than primary lactose intolerance
•Malabsorption Disorders (cont’d)
•Nutrition therapy
–Nutrition therapy for lactose intolerance is to reduce lactose to the maximum amount tolerated by the individual
–A lactose-free diet is not realistic
•Question
•In lactose intolerance, undigested lactose increases the ______of the intestinal contents.
a. Secretions
b. Osmolality
c. Acidity
d. Liquidity
•Answer
b. Osmolality
Rationale: Particles of undigested lactose increase the osmolality of the intestinal contents, which may lead to osmotic diarrhea.
•Malabsorption Disorders (cont’d)
•Inflammatory bowel disease (IBD)
–Primarily refers to 2 chronic inflammatory GI diseases
oCrohn’s disease
oUlcerative colitis
–IBD is believed to be caused by an abnormal immune response to a complex interaction between environmental and genetic factors
•Malabsorption Disorders (cont’d)
•Inflammatory bowel disease (IBD) (cont’d)
–Characterized by periods of exacerbation and remission
–Share symptoms and treatment
•Malabsorption Disorders (cont’d)
•Inflammatory bowel disease (IBD) (cont’d)
–Nutrition therapy
oDepends on the presence and severity of symptoms, the presence of complications, and the nutritional status of the patient
oDiet restrictions kept to a minimum
oPatients are often reluctant to eat
oCrohn’s disease is more likely to cause nutritional complications
•Malabsorption Disorders (cont’d)
•Inflammatory bowel disease (IBD) (cont’d)
–Nutrition therapy(cont’d)
oFocus of therapy for acute exacerbation of IBD is to correct deficiencies by providing nutrients in a form the patient can tolerate
oFor patients consuming an oral diet, low fiber is recommended to minimize bowel stimulation
oProtein and calorie needs are elevated to facilitate healing
oDiet modifications are made according to symptoms
•Malabsorption Disorders (cont’d)
•Celiac disease
–A genetic autoimmune disorder characterized by chronic inflammation of the proximal small intestine mucosa
–Related to a permanent intolerance to certain proteins found in wheat, barley, and rye
–Malabsorption of carbohydrates, protein, fat, vitamins, and minerals may occur, resulting in diarrhea, flatulence, weight loss, and vitamin and mineral deficiencies
•Malabsorption Disorders (cont’d)
•Celiac disease (cont’d)
–Symptoms and their severity vary depending on the patient’s age and the duration and extent of the disease
–Classic symptoms in children are diarrhea, abdominal distention, and failure to thrive
–Adults present with diarrhea, constipation, weight loss, weakness, flatus, abdominal pain, and vomiting
•Malabsorption Disorders (cont’d)
•Celiac disease (cont’d)
–Atypical presentations
–In 0% to 20% of people with celiac disease, dermatitis herpetiformis is the presenting symptom
–Symptoms of dermatitis herpetiformis respond to a gluten-free diet
–Malabsorption Disorders (cont’d)
•Celiac disease (cont’d)
–People who have a first-degree relative with celiac disease, people with Down syndrome, and those with an autoimmune disease are at risk for celiac disease
–Untreated celiac disease is associated with an increased incidence of small-bowel cancers and enteropathy-associated T-cell lymphoma
•Malabsorption Disorders (cont’d)
•Celiac disease (cont’d)
–Nutrition therapy
oOnly scientifically proven treatment for celiac disease is to completely and permanently eliminate gluten from the diet
oLactose intolerance secondary to celiac disease may be temporary or permanent
•Malabsorption Disorders (cont’d)
•Celiac disease (cont’d)
–Nutrition therapy (cont’d)
oA gluten-free diet requires a major lifestyle change
oExpensive
•Short-bowel syndrome (SBS)
–Occurs when the bowel is surgically shortened to the extent that the remaining bowel is unable to absorb adequate levels of nutrients to meet the individual’s needs
•Question
•Who is at risk for celiac disease?
a. People with a second-degree relative who has celiac disease
b. People who have lactose intolerance
c. People who have congenital diseases
d. People who have an autoimmune disease
•Answer
d. People who have an autoimmune disease
Rationale: People who have a first-degree relative with celiac disease, people with Down syndrome, and those with an autoimmune disease are at risk for celiac disease.
•Malabsorption Disorders (cont’d)
•Short-bowel syndrome (SBS) (cont’d)
–Most common reasons for extensive intestinal resections that result in SBS
oCrohn’s disease
oTraumatic abdominal injuries
oMalignant tumors
oMesenteric infarction
•Malabsorption Disorders (cont’d)
•Short-bowel syndrome (SBS) (cont’d)
–Nutrition complications experienced by people with short-bowel syndrome depend on the amount and location of resected and remaining bowel
oPatients who have 150 cm or more of remaining small bowel without a colon, or 60 to 90 cm of small bowel with a colon, initially require TPN and may progress to an oral diet over a 1- to 2-year period
•Malabsorption Disorders (cont’d)
•Short-bowel syndrome (SBS) (cont’d)
–Factors that influence adaptation
oLength of remaining jejunum and/or ileum and whether the colon is present
oPatient’s age
oWhether the ileocecal value remains
oHealth of the remaining bowel
oHealth of the stomach, liver, and pancreas
•Malabsorption Disorders (cont’d)
•Short-bowel syndrome (SBS) (cont’d)
–Nutrition therapy
oIn the early months after bowel surgery, TPN is the major source of nutrition and hydration
oConsuming intact nutrients promotes bowel adaptation because they stimulate blood flow to the intestine and the secretion of pancreatic enzymes and bile acids
•Malabsorption Disorders (cont’d)
•Short-bowel syndrome (SBS) (cont’d)
–Nutrition therapy (cont’d)
o6 to 8 small meals/day
oIf the patient’s colon is intact, fat intake is restricted to avoid steatorrhea and increased fluid losses
•Conditions of the Large Intestine
•Irritable bowel syndrome (IBS)
–Most frequently diagnosed digestive disorder in the U.S.
–Many factors involved in its etiology
–Symptoms include lower abdominal pain, constipation, diarrhea, alternating periods of constipation and diarrhea, bloating, and mucus in the stools
–Can significantly impair quality of life
•Conditions of the Large Intestine (cont’d)
•Irritable bowel syndrome (IBS) (cont’d)
–Nutrition therapy
oInconclusive evidence for any of the current treatments used for IBS
oPharmacologic treatment options
Meet with limited success
oComplementary therapies
oElimination diet
•Conditions of the Large Intestine (cont’d)
•Irritable bowel syndrome (IBS) (cont’d)
–Nutrition therapy (cont’d)
oPrebiotics
oGrade A level evidence exists for the use of 5 g of guar gum daily
Guar gum is a soluble, non-gelling fiber
–Conditions of the Large Intestine (cont’d)
•Diverticular disease
–Diverticula are caused by increased pressure within the intestinal lumen
–Usually asymptomatic
–Diverticulitis occurs when diverticula become inflamed
–Conditions of the Large Intestine (cont’d)
•Diverticular disease (cont’d)
–Symptoms of diverticulitis
oCramping
oAlternating periods of diarrhea and constipation
oFlatus
oAbdominal distention
oLow-grade fever
•Conditions of the Large Intestine (cont’d)
•Diverticular disease (cont’d)
–Potential complications
oOccult blood loss and acute rectal bleeding leading to iron-deficiency anemia
oAbscesses and bowel perforation leading to peritonitis
oFistula formation causing bowel obstruction
oBacterial overgrowth (in small-bowel diverticula) that leads to malabsorption of fat and vitamin B12
oConditions of the Large Intestine (cont’d)
•Diverticular disease (cont’d)
–Nutrition therapy
oHigh-fiber intake may prevent and improve symptoms of diverticulosis and prevent diverticulitis
oAvoid nuts, seeds, and popcorn
•Conditions of the Large Intestine (cont’d)
•Diverticular disease (cont’d)
–Nutrition therapy (cont’d)
oDuring an acute phase of diverticulitis:
Patients are NPO until bleeding and diarrhea subside
Oral intake resumes with clear liquids and progresses to a low-fiber diet until inflammation and bleeding are no longer a risk
A high-fiber diet is recommended unless symptoms of diverticulitis recur
•Question
•Is the following statement true or false?
Pharmacologic treatment options meet with limited success in diverticular disease.
•Answer
False.
Rationale: Antidiarrheals, antispasmodics, and antidepressants are pharmacologic treatment options that meet with limited success in irritable bowel syndrome.
•Conditions of the Large Intestine (cont’d)
•Ileostomies and colostomies
–Performed after part or all the colon, anus, and rectum are removed
–Potential nutritional problems
–The smaller the length of remaining colon, the greater the potential for nutritional problems
–Ileostomies cause a decrease in fat, bile acid, and vitamin B12 absorption
•Conditions of the Large Intestine (cont’d)
•Ileostomies and colostomies (cont’d)
–Effluent from an ileostomy is liquidy, and fluid and electrolyte losses are considerable
–Effluent through a colostomy varies from liquid to formed stools
–Nutrition therapy
oGoals of nutrition therapy for ileostomies and colostomies are to minimize symptoms and replenish losses
•Conditions of the Large Intestine (cont’d)
•Ileostomies and colostomies (cont’d)
–Nutrition therapy (cont’d)
oInitially only clear liquids that are low in simple sugars
oAdvanced slowly based on individual tolerance
oFear of eating is common
oA near-regular diet resumes 6 to 8 weeks post-op
oObtaining adequate fluid and electrolytes is a major concern
–Disorders of the Accessory GI Organs
•Liver disease
–After absorption, almost all nutrients are transported to the liver
–Vital for detoxifying drugs, alcohol, ammonia, and other poisonous substances
–Liver damage can have profound and devastating effects on the metabolism of almost all nutrients
–Failure can occur from chronic liver disease or secondary to critical illnesses
•Disorders of the Accessory GI Organs (cont’d)
•Liver disease (cont’d)
–Early symptoms of hepatitis
oAnorexia, nausea and vomiting, fever, fatigue, headache, and weight loss
–Later
oDark-colored urine, jaundice, liver tenderness, and possibly liver enlargement may develop
–Cell damage reversible with proper rest and nutrition
•Disorders of the Accessory GI Organs (cont’d)
•Liver disease (cont’d)
–Acute hepatitis advances to chronic hepatitis, which may lead to cirrhosis, liver cancer, and liver failure
–Glucose intolerance is common
–Cirrhosis can progress to hepatic encephalopathy and hepatic coma
–Liver “fails” when liver cell loss is extensive
–Disorders of the Accessory GI Organs (cont’d)
•Liver disease (cont’d)
–Nutrition therapy
oObjectives of nutrition therapy for liver disease are to avoid or minimize permanent liver damage, promote liver cell regeneration, restore optimal nutritional status, alleviate symptoms, and avoid complications
oRegeneration may not be possible
oPatients with acute hepatitis have difficulty consuming an adequate diet
•Disorders of the Accessory GI Organs (cont’d)
•Liver disease (cont’d)
–Nutrition therapy (cont’d)
oMalnutrition is common among patients with cirrhosis
oMeeting nutrient and calorie needs is difficult
–Disorders of the Accessory GI Organs
•Nutrition therapy for liver transplantation
–Treatment option for patients with severe and irreversible liver failure
–Moderate to severe malnutrition increases the risk of complications and death after transplantation
–Not one specific post-transplant diet
–Small frequent meals and commercial supplements may help maximize intake
•Disorders of the Accessory GI Organs (cont’d)
•Nutrition therapy for liver transplantation (cont’d)
–Long-term complications associated with immunosuppressive therapy, such as excessive weight gain, hypertension, hyperlipidemia, osteopenic bone disease, and diabetes, may require nutrition therapy
–Use of immunosuppressant drugs elevates the importance of safe food handling practices to avoid foodborne illness
•Disorders of the Accessory GI Organs (cont’d)
•Pancreatitis
–Inflammation of the pancreas
–People with pancreatitis may also develop hyperglycemia related to insufficient insulin secretion
–Alcohol abuse and gallstones account for 75% to 85% of cases of acute pancreatitis
–Acute pancreatitis that is not resolved or recurs frequently can lead to chronic pancreatitis
oCharacterized by scarring, fibrosis, and loss of organ function
•Disorders of the Accessory GI Organs (cont’d)
•Pancreatitis (cont’d)
–Seventy percent of cases are caused by alcohol abuse; 20% are idiopathic
–Characterized by intermittent pain that is made worse by eating
–Malabsorption does not occur until pancreatic enzyme secretion is less than 10% of normal
•Disorders of the Accessory GI Organs (cont’d)
•Pancreatitis (cont’d)
–Nutrition therapy
oAcute pancreatitis is treated by reducing pancreatic stimulation
oIn mild cases, the patient is given pain medications, IV therapy, and nothing by mouth (NPO)
oSmall, frequent meals may be better tolerated initially because they help to reduce the amount of pancreatic stimulation at each meal