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Case 3: Beth Crawford - Diagnosis & Treatment

Diagnosis

Determine Body Mass Index

BMI

Beth is underweight, having lost a total of 17lbs since the surgery. She is now has a BMI of 18 kg/m2. Normal BMI is 18.5-24.9 kg/m2.

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) encompasses at least two forms of chronic intestinal inflammation: Crohn's disease (CD) and ulcerative colitis (UC). In UC, the inflammation is confined to the colonic mucosa and inflammation includes the rectum and extends proximally to varying degrees. CD is a transmural inflammatory process which may occur at any site throughout the gastrointestinal tract. The disease is segmental, with scattered spared areas of the gastrointestinal tract. The distribution of the inflammation varies; however, terminal ileum involvement is often characteristic of Crohn's disease. For further explanation see The Merck Manual of Diagnosis and Therapy Section 3. Gastrointestinal Disorders. Chapter 31. Inflammatory Bowel Disease.

Figure 8-4: Complications of Crohn's Disease
[Source: Mayo Clinic. Mayo Foundation for Medical Education and Research. Coping with Crohn's.]

Table 8-5: Patterns of Crohn's Disease
Terminal ileal disease 25-35%
Involvement of the terminal ileum and colon 35-45%
Isolated colonic disease 15-25%
Proximal or diffuse small intestinal inflammation (least common) 5-10%
Following intestinal resection, CD invariably reappears in a new site, most commonly proximal to the anastomoses.  
Source: Shils, Maurice E.; Olson, James A.; Shike, Moshe; Ross, A. Catherine; editors. Modern nutrition in health and disease. 9th ed. Philadelphia: Lea and Febiger, 1999. p.1141

The impact on the nutritional state of the patient with IBD varies depending upon the site, nature, and extent of inflammation.

Enteric losses: During periods of active inflammation (also known as "flares" of the disease) the bowel "weeps" protein, blood, minerals, electrolytes and trace elements.

Short Bowel Syndrome

Definition

Short bowel syndrome is a collection of signs and symptoms used to describe the nutritional and metabolic consequences following major resections of the small intestine. The syndrome is characterized by diarrhea, fluid and electrolyte abnormalities, malabsorption, and weight loss. Patients who have not had intestinal resections but have a marked reduction of small bowel absorptive surface area (e.g. diffuse inflammatory bowel disease, celiac disease, radiation enteritis) may have he same nutritional sequelae.

In general, the severity of malabsorption in short bowel syndrome depends on five factors:

  1. the extent of the resection with consequent loss of absorptive surface area,
  2. the site of resection (jejunal, ileal, and colonic) with loss of site-specific transport functions and gastrointestinal (GI) hormone synthesis,
  3. the presence or absence of the ileocecal valve,
  4. the sequential adaptation of the remaining intestine, and,
  5. possible residual disease in the preserved bowel.

The complex interactions of these factors determine the outcome of patients with short bowel syndrome. The spectrum of this syndrome ranges from limited small bowel resections to extensive small intestinal and colonic resections that result in severe panmalabsorption and require long-term parenteral nutrition for survival.

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Figure 8-5: Short Bowel Syndrome Overview
[Source: John Kerner, MD]

Figure 8-6: Underlying Conditions of Short Bowel Syndrome
[Source: John Kerner, MD]

Figure 8-7: Parenteral Nutrition for Short Bowel Syndrome
[Source: John Kerner, MD]

Fat absorption in Crohn's disease may be altered by loss surface area due to inflammation or resection as well as a decrease in bile salts secondary to malabsorption of bile acid in the ileum. Normally there is entero-hepatic recycling of bile salts. They are reabsorbed in the ileum, circulated to the liver, and returned back to the intestinal lumen. In patients with the ileum partially resected, bile salts may be lost in the stool. Fat and fat-soluble vitamins A, D, E, and K absorption decrease with decreased fat absorption. The severity of the fat malabsorption is dependent upon the extent of ileal resection. With less than 30cm resected, malabsorption is normally mild. If the ileo-cecal valve is resected, the fecal fat excretion increases, and bacterial overgrowth is likely to occur, leading to additional maldigestion. This maldigestion occurs as bacteria tend to ferment carbohydrate producing lactic acid, leading to acidic stools and osmotic diarrhea.

Specific nutrient malabsorption is dependent upon the site of involvement. Malabsorption of vitamin B12 and bile salts is most common in patients with active ileal disease and, among those patients undergoing ileal resections, depending on the amount of remaining length of the ileum.

Table 8-6: Factors Causing Malnutrition in Inflammatory Bowel Disease
Decreased nutrient intake Weight loss
Disease related anorexia Iatrogenic (unjustified dietary restrictions)

Malabsorption Diminished absorptive surface (disease, fistula, resection)
Bacterial overgrowth
Bile salt deficiency
Increased gut losses Protein-losing enteropathy
Electrolytes, minerals, trace metals (diarrhea and fistula)
Bleeding
Increased requirements Sepsis, fever
Increased cell turnover
Source: Shils, Maurice E.; Olson, James A.; Shike, Moshe; Ross, A. Catherine; editors. Modern nutrition in health and disease. 9th ed. Philadelphia: Lea and Febiger, 1999. p. 1143

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Evaluation

Beth is losing weight. This is due to either decreased appetite associated with a Crohn's disease "flare" or to malabsorption due to short bowel syndrome. Her diet history reflects a high percentage of calories as fat and simple sugars as she tends to select fast food. Her laboratory value of low albumin reflects intestinal "weeping" leading to protein loss in the stool, or possibly decreased oral protein intake. The low zinc and magnesium lab values reflect fluid losses through diarrhea. Vitamin B12 intrinsic factor complex (it couples with intrinsic factor secreted in the stomach) is absorbed by the ileum. She has a low B12 secondary to the ileal resection. Her prolonged Prothrombin time reflects vitamin K deficiency secondary to resection of some of the jejunum and lack of adequate bile salts to help reabsorb fat and fat soluble vitamins, secondary to the extensive ileal resection.

Strategies

Given her symptoms, the differential diagnosis includes:
  1. "flare" of the patient's Crohn's disease,
  2. infectious diarrhea, or
  3. malabsorption secondary to short bowel syndrome.

To rule out infection, Beth had stools for virus, clostridium difficile (common in patients with inflammatory bowel disease), stool culture, and stool for ova and parasites. The infectious work-up was entirely negative. To evaluate for possible Crohn's disease "flare", she had a sedimentation rate and a serum alpha-1-antitrypsin (an acute phase reactant), a stool guaiac, and a stool for alpha-1-antitrypsin (a measure of protein loss in the stool). All four laboratory tests were normal, arguing strongly against a "flare" of the Crohn's disease. She had been placed on 6-mercaptorine and Pentasa® post-operatively. Both drugs, independently, have demonstrated benefits in preventing postoperative recurrence of Crohn's disease. Given the mild laboratory abnormalities, the likely explanation was nutrient deficiencies secondary to the her underlying short bowel syndrome.

The goals of the nutrition therapy are to provide adequate intake, repletion of low nutrient status, promote healing and decrease symptoms causing poor appetite. To control diarrhea, a moderate fat, low fiber, low lactose, and high complex carbohydrate diet is recommended. Malabsorption of other disaccharides causes decrease in stool Ph. A stool Ph of less that 6 can guide you to the elimination of other sugars. Malabsorption of lactose may occur because of decreased brush border lactase activity. Total elimination is rarely necessary. Beth and patients like her can take lactase enzyme pills and use lactose reduced milk products. Small frequent feedings will reduce the amount of food presented to the damaged bowel, resulting in improved tolerance.

Beth will need a high calorie diet, with particular emphasis on foods enriched or fortified to restore body weight. If she is unable to take adequate calories in food she will need to use a liquid nutritional supplement, a high calorie drink designed to replete nutrients and provide energy and protein. She will need vitamin and mineral supplementation as outlined in the following table:

Table 8-7: Vitamin and Mineral Supplements for Short Bowel Patients
Supplement Dose Route Alternative Recommendations
Multivitamin with minerals 1 prenatal vitamin/day (will contain folic acid) p.o.  
Vitamin K 5 mg/day p.o.  
Vitamin D 50,000 IU/2-3 times per week p.o. 400-900 IU/day p.o.
Vitamin B121 100-500 µg Q. 1-2 mo. I.M. 1000 µg I.M./Q 2-3 mo.
Magnesium gluconate (Magonate) 54 mg of elemental mg tid or qid p.o. 24-48 mEq/day p.o. (usually tolerated without worsening diarrhea)
Magnesium sulfate 290 mg elemental mg 1-3 times /week I.M./I.V. 2 g. (16 mEq) Mg++ i.M. or I.V. as needed
Zinc gluconate or zinc sulfate 25 mg of elemental zinc/day plus 100 mg/L intestinal output p.o. 45 mg effervescent tablets of 22.5 mg of elemental zinc
11 Vitamin B12 intranasal (Nascobal®) 500 µg once weekly dose

500 µg/0.1mL after patients have been stabilized with injection therapy

intranasal  

[Source: Chan MF, Klein S: Short bowel syndrome. IN: Rombeau, John L. Rolandelli, Rolando. Clinical nutrition : enteral and tube feeding 3rd ed. Publisher: Philadelphia : W.B. Saunders Co., c1997. p.575-587.
Source for alternative recommendations: Forbes A, Chadwick C: Short bowel syndrome. IN: The A.S.P.E.N. Nutrition Support Practice Manual, 1998. p15-1 to 15-10.]

Beth is to return in 3 months to evaluate weight and check nutrient status with labs.


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Stanford Nutrition Project curriculum has been developed by a collaboration of SUMMIT and the Office of Medical Education and was partially funded by Nutrition Academic Award Grant number HL04325-03 from the National Heart Lung and Blood Institute (NIH).