Newsletter

[ Vol. 11 No. 2 ] (May - August 2010 )
Management of short bowel syndrome

Khursheed Jeejeebhoy
Gastroenterology Division, St Michael’s Hospital, Toronto, Ontario, Canada

INTRODUCTION
The gastrointestinal tract is designed to act is a single unit from the stomach to the colon. Therefore, in order to understand the factors that contribute to intestinal failure it is necessary to identify the role of each of the components in aiding the digestion and absorption of food and in the maintenance of the nutritional status of the host.

DEFINITION
Short Bowel occurs when gastrointestinal function is inadequate to maintain the nutrition and hydration of the individual without supplements given orally or intravenously. 

PHYSIOLOGICAL CONSIDERATIONS
Stomach
The rate of gastric emptying regulates the progress of the meal through the small bowel.

Small Bowel
Small bowel motility is three times slower in the ileum than in the jejunum. In addition the absorptive processes are different in the jejunum as compared with the ileum. These differences depend partly on the nature of the electrolyte transport processes and partly on the permeability of the intercellular junctions. It has been estimated that the efficiency of water absorption is 44% and 70% of the ingested load in the jejunum and ileum respectively. For sodium the corresponding estimates are 13% and 72%. Hence the ileum is important in the conservation of fluid and electrolytes.

Colon
The colon has the slowest transit varying between 24-150 hours. The colon becomes an important organ for fluid and electrolyte conservation and for the salvage of malabsorbed energy substrates in patients with a short bowel. 

IMPLICATIONS FOR MANAGEMENT OF SHORT BOWEL SYNDROME
Jejunal resection with intact and disease free ileum and colon:
Patients in this category can be fed orally immediately and rarely have any problems. However disease in the ileum and colon may cause the same loss of function as a resection of these segments of the bowel.

Ileal resection of less than 100 cm with colon largely intact:
Patients in this category have so called bile salt induced diarrhea, and are best helped by the administration of 4 g of cholestyramine three times a day to bind bile salts left unabsorbed by the resected ileum. Vitamin B12 absorption should be measured and if low should be injected intramuscularly in doses of 100 to 200 ug per month. 

Ileal resection of more than 100 to 200 cm with colon largely intact:
This group of patients has little difficulty in maintaining nutrition with an oral diet, but has fatty acid diarrhea. For such a patient, fat restriction is mandatory. With the larger resection the bile salt pool is depleted and cholestyramine is no longer beneficial.  Parenteral vitamin B12 replacement is required.

Resection in excess of 200 cm of small bowel and lesser resection with associated colectomy:
Patients of this class require the graduated adaptation program indicated previously under general considerations.

Resection leaving less than 60 cm small bowel or only duodenum: Massive bowel resection:
Patients in this category need HPN indefinitely. However many patients even in this category may show a surprising degree of adaptation and require less parenteral nutrition and benefit from orally absorbed nutrients. The indication to reduce parenteral nutrition is weight gain beyond the desired limit and the fact that reduced infusion dose not cause electrolyte imbalance and dehydration.

From   
PENSA 2009
“Energizing Nutrition Support Practice for Life”
June 5-7 2009, Shangri-La Hotel, Kuala Lumpur, Malaysia 
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