Pediatric Short Bowel Syndrome Treatment & Management

Updated: Aug 15, 2016
  • Author: Carmen Cuffari, MD; Chief Editor: Jatinder Bhatia, MBBS, FAAP  more...
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Treatment

Medical Care

The management of short bowel syndrome (SBS) requires an aggressive multidisciplinary approach that is most often tailored to the individual needs of the patient. [2] Nutrition plays an important role in the management of short bowel syndrome. The institution of early and aggressive enteral therapy is the most important stimulus for intestinal adaptation and the eventual discontinuation of parenteral therapy.

Parenteral nutrition

The length and function of the remaining intestine and the presence of normal physiologic mechanisms that regulate intestinal transit time, including the ileocecal valve and colon, determine whether the patient requires a limited course of specialized enteral therapy or prolonged total parenteral nutrition (TPN).

In 1991, Goulet et al studied the relative importance of several clinical factors in predicting the long-term needs for parenteral nutrition. [5] In 54 neonates who underwent extensive small-bowel resection, the presence of less than 40 cm of small intestine in children with either colonic resection or an absent ileocecal valve had a strong association with a prolonged need for parenteral nutrition (>48 mo).

Although this has been the experience at most pediatric tertiary care centers that care for children with short bowel syndrome, the authors' collective experience at The Johns Hopkins Children’s Center suggests that, with aggressive introduction of continuous modular enteral feeds and selective weaning of protein and fats from the parenteral nutrition, children with extensive small bowel resection may be salvaged sooner and weaned off of parenteral nutritional support. The ultimate goal is avoiding the need for either liver or multivisceral transplantation.

Teduglutide has been shown to reduce the need for parenteral support. [6] Studies have found that treatment with teduglutide has resulted in enhancement or restoration of the structural and functional integrity of the remaining intestine and has reduced the need for parenteral nutrition support in patients with short bowel syndrome and intestinal failure. [7]

Excessive fluid losses

Massive fluid and electrolyte losses are usually observed during the first week after excessive intestinal resection. Patients with short bowel syndrome most often require aggressive resuscitation with fluids or parenteral nutrition, or both. Instituting enteral therapy as soon as possible is very important in order to facilitate the adaptive intestinal response.

In the early postoperative period, monitor serum electrolytes and a comprehensive biochemical pattern daily. When these values have stabilized, monitor them on a biweekly or triweekly basis. The hypersecretion noted within the first 12 months postresection is usually treated with histamine 2 (H2)–receptor antagonists or proton pump inhibitors.

The provision of adequate parenteral fluid replacement needs may be ongoing depending on the amount of stool or ostomy output. Indeed, enteral nutrition can cause significant osmotic diarrhea.

Malabsorption

Extensive jejunal resection leads to carbohydrate malabsorption. The undigested foods produce an osmotic diarrhea typical of most patients with short bowel syndrome. The proximal small bowel is also important in the absorption of proteins, fat, and certain micronutrients, including copper.

Extensive resection of the ileum may lead to severe malabsorption of bile salt and vitamin B-12. Bile salt malabsorption produces a choleretic diarrhea. Furthermore, bile salt depletion affects fat absorption, thereby worsening steatorrhea and fat-soluble vitamin malabsorption. Ileal resection leads to the malabsorption of bile salts and an abnormal bile acid pool that leads to the formation of a lithogenic bile and cholelithiasis.

The ileocecal valve is important in preventing bacterial overgrowth. Problems associated with proximal small-bowel overgrowth include deconjugation of bile salts and depletion of bile salt stores. Bacteria often compete for vitamin B-12, which may facilitate a pernicious anemia. Bacteria overgrowth also leads to carbohydrate malabsorption, worsening of osmotic diarrhea, and increased risk of metabolic acidosis and dehydration. Treatment is generally aimed at lessening the degree of bacterial overgrowth with antibiotic therapy, including administration of metronidazole alternating with either kanamycin or oral gentamicin.

Motility disturbances

Patients with short bowel syndrome have a decrease in intestinal transit time. Patients with extensive proximal small-bowel resection have increased gastric emptying, thereby further decreasing intestinal transit time.

The absence of normal physiologic mechanisms that increase intestinal transit, including the ileocecal valve and colon, also shortens intestinal transit time. However, if the existing small bowel or colon shows signs of dysmotility due to fibrosis or surgical narrowing, stagnant bowel contents may aggravate an existing bacterial overgrowth, thereby worsening malabsorption and diarrhea.

Small-bowel overgrowth also leads to d-lactic acidosis and may be associated with CNS disturbances. Antibiotics are used to prevent small bowel overgrowth and should be cycled on a weekly or biweekly basis. Numerous potential antibiotic therapies can be used. At the Johns Hopkins Children’s Center, metronidazole, kanamycin, nitazoxanide and rifaximin are the preferred therapies used in managing patients with small bowel bacterial overgrowth.

Short bowel syndrome associated colitis is not an infrequent complication. Patients often present with hematochezia and have histologic signs of colitis on intestinal biopsies.

In patients where the colon is not removed, histological signs of colonic mucosal hypertrophy that serves to increase colonic fluid and electrolyte absorption are noted. Studies have shown that these adaptive responses may actually be hormonally mediated by various growth factors, including glucagonlike polypeptides. Although a functional colon is always preferred in short bowel syndrome, patients who exhibit colonic dysmotility may generally achieve a more rapid advancement with enteral feeds with a diversion proximal colostomy. The authors' experience at The Johns Hopkins Children’s Center has shown that prokinetic agents such as erythromycin and raglan have limited efficacy in improving residual bowel function, especially in patients with significant small and large bowel dysmotility.

Among patients with significant dysmotility issues, the authors' experience has shown that a diverting ileostomy can be used to prevent the stagnation of stool. By establishing a good flow of stool, enteral feeds are allowed to continue and be maximized. Rectal tubes can also be used to facilitate the flow of stool, albeit somewhat problematic in the older child. Among those children that a rectal tube is only partially effective, a diversion ileostomy can be performed.

Patients with ongoing issues of dysmotility should have a small bowel enema performed to rule-out intestinal strictures. Those lesions should be dealt with by surgery. Furthermore, proximal GI issues, including gastroparesis can be medically treated; however, the authors' experience has shown that among the most refractory cases that postpyloric feeding tubes are required.

Gastric acid hypersecretion

Gastric acid hypersecretion is common in patients with short bowel syndrome. The degree of hypersecretion is proportional to the degree of bowel resected. Hypersecretion may contribute to malabsorption by inactivating pancreatic enzymes and, thus, interfering with fat absorption. The usual treatment is with H2 blockers. [8]

Although the usual treatment is with H2 blockers, the availability of proton pump inhibitors especially in pharmacological forms conducive to the needs of children with enteral feeding tubes has now been the treatment therapy of choice in managing children with short bowel syndrome and gastric acid hypersecretion.

Medical therapies

Codeine and loperamide can be used in pediatric patients to slow intestinal transit time; however, results have been mixed because of concerns for worsening of bacterial overgrowth. Octreotide is rarely used to limit the amount of intestinal losses after bowel resection. Its use in pediatric patients is controversial because of concerns of the effect on growth and worsening cholestatic liver disease. Cholestyramine has been used as a means of binding bile salts in patients with choleretic diarrhea. Antibiotics are sparingly used to prevent small-bowel overgrowth.

Children, especially young infants, also have a greater capacity to adapt than adults in response to massive small bowel resection. Numerous physiological responses to short bowel syndrome are observed. Although the small intestine is unable to extend itself in length, it does have the capacity to hypertrophy by increasing the number and size of intestinal villi, as well as crypt depth. All these adaptive functions are important in increasing intestine’s absorptive surface area by increasing mucosal mass.

Several mechanisms are involved in stimulating mucosal hypertrophy, including hormones secreted by the small bowel on exposure to intraluminal nutrients, as well as intestinal growth factors produced by both the pancreas and biliary system. Intestinal growth factors, including glucagonlike peptide and other proglucagon-derived peptides produced by the epithelium have been shown to stimulate intestinal growth and adaptation. Similarly, non-GI hormones (eg, cortisol, thyroxin) may also be involved. Mucosal hyperplasia also depends on exposure to intraluminal contents. Certain dietary components have a trophic influence on the intestinal mucosa; thus, an aggressive provision of enteral nutrition can be regarded as an important therapeutic tool in allowing for intestinal adaptation.

Glutamine is an important fuel for the intestinal mucosa and has been shown to stimulate mucosal growth. However, most clinical trials have not shown any selective advantage with the supplementation of children with short bowel syndrome with pharmacological doses of glutamine. [9] The same can also be said with the supplementation of pharmacological doses of cholecystokinin.

An uncontrolled clinical trial using intravenous cholecystokinin in patients with short bowel syndrome and cholestasis did not show any added therapeutic benefit. The authors are also in the process of investigating the usefulness of choline therapy. The authors' experience has shown that the best way of managing cholestasis is usually through aggressive weaning of parenteral nutritional therapy because patients with short bowel syndrome show improved tolerance of enteral feeds. If parenteral nutrition cannot be entirely weaned, the authors tend to selectively eliminate amino acid and fat supplementation, assuming that the patient’s nitrogen balance and caloric needs are being met through enteral nutrition.

Teglutide is synthetic analogue of GLP-2, a naturally occurring gut peptide with trophic effects on the intestinal villi. This drug has been approved by the US Food and Drug Administration (FDA) for use among adult patients with short bowel syndrome. It has been shown to increase villous height and crypt depth among patients with short bowel syndrome and to increase both fluid and macronutrient absorption. Most studies showed that the drug was well-tolerated; however, the potential risk for intestinal adenomas demands that all patient undergo a screening colonoscopy prior to its use. [58] The drug is presently being studied in children with short bowel syndrome.

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Surgical Care

Surgical care is related to venous access (ie, central line placement to provide TPN). The loss of intravenous access through repeated episodes of sepsis and thrombosis can lead to the early need for intestinal transplantation despite good hepatic function. Surgery may be required for gastrostomy tube placement to provide for enteral access.

Intestinal lengthening procedures and transplantation are always avoided if at all possible. Several attempts at increasing bowel length through surgical means have been made over the last decade. The bowel is transected longitudinally to preserve the blood supply. The largest experience comes from the University of Nebraska. In this experience, surgical intervention improved intestinal adaptability and weaning from parenteral nutrition in a dozen patients. However, with repeated surgical interventions, the risk of intestinal stricture formation increases, as well as the risk of small-bowel obstruction secondary to adhesion formation.

Small-bowel transplantation has shown mixed success. The problems associated with transplantation, including the need for immunosuppression and the risk for intestinal rejection and lymphoproliferative disease, has limited this treatment option for most patients with short bowel syndrome unless absolutely necessary in patients with associated severe advanced liver disease and those with major vascular access problems. Isolated orthotopic liver transplantation without small-bowel transplantation has been demonstrated to be effective.

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Consultations

The authors' experience has also shown that most catheter infections can be managed on an out-patient basis. [10] With a robust nursing home support mechanism, most infections, including fungal infections can be managed effectively at home. This clinical approach requires a committed family willing to take on this responsibility in administering intravenous antibiotics and a specialized medical support system that sustains an optimized level of communication with the family, especially during the weekends and evenings. When sepsis is present with no identifiable bacterial source, the aid of an infectious disease specialist may be requested.

In addition to consultation with a gastroenterologist, in the setting of fungemia, consulting an infectious disease specialist to guide antifungal therapy is best and, in the setting of liver or intestinal failure, consult a transplant surgeon.

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Diet

Enteral therapy

In infants with massive small-bowel resection, enteral nutrition is initiated very quickly by using elemental formulas. The mixture of monosaccharides and polysaccharides is preferred to disaccharides in order to limit osmotic load, in combination with long-chain triglycerides (LCT) and medium-chain triglycerides (MCT). The authors favor starting with formulas that are either one-fourth or one-half strength, depending on the patient's tolerability, and increasing in volume before increasing energy density. Oligopeptide formulas are better absorbed than elemental amino acid formulas because di-tripeptide absorption exceeds that of amino acids.

MCTs are important in the dietary management of patients with short bowel syndrome because they are readily absorbed in the stomach and proximal small bowel, thereby improving fat and total energy absorption. Current recommendations are to use MCTs as the main source of fat and energy needs. Long-chain fatty acids are required to prevent essential fatty acid deficiency and should make up approximately 10% of the patient's energy needs. Long-chain fatty acids may have a trophic effect on the intestinal mucosa.

The question of fat intolerance has always been a point of contention; however, the use of long-chain fats, which have increased energy density, is usually better tolerated than use of carbohydrates. Testing the tolerability of either fats or carbohydrates and adjusting the modular formula accordingly is advisable. In some cases, providing carbohydrates parenterally and providing fats enterally is preferred in order to improve a patient's tolerance. The use of continuous enteral feeds is better tolerated than bolus feeds in patients with small-bowel resection. An increase in stool output with the appearance of fecal-reducing substances is an indication that the patient may have reached the tolerance limit.

Enteral nutrition remains the lone medical therapy that can facilitate intestinal adaptation. The residual bowel must be constantly exposed to nutrients in order to allow the bowel to adapt. Hence, the physician must be able to allow for substantial stool volume and frequency, as long as it does not compromise the child's hydration, acid base balance, and serum electrolyte levels. A common mistake is the tendency to either stop enteral feeds or substantially lower the volume and frequency of feeds in response to changes in stool volume. Most fluid and electrolyte perturbations that result from short bowel syndrome, or in response to modifications in enteral nutritional therapy, can be easily compensated through an adjustment in the parenteral formula. If possible, the physician should avoid altering the rate or the concentration of the enteral formula too aggressively, in order to allow the adaptive process to proceed.

Many animal models have shown that the bowel is very sensitive to starvation. In the absence of enteral nutrition, the crypt cell population decreases and epithelial cell cycle increases, thereby decreasing the proliferation of the intestinal epithelium. In contrast, in response to a continual and large supply of enteral nutrients, crypt cells proliferate, leading to an increase in crypt depth and lengthening of the intestinal villi. An increase in the absorptive area does not always coincide with functional adaptation.

The production of digestive enzymes and nutrient receptors is in direct response to the quality and quantity of intestinal nutrients. The physician must ensure a constant provision of macronutrients, in order to facilitate this adaptive process. The adaptive process may, in large part, also depend on the production of trophic intestinal hormone and secretions that are produced in response to nutritional therapy.

In a healthy individual, other than fluid and calcium absorption, the colon has a limited absorptive capacity; however, in patients with short bowel syndrome, the colon may assume an increased nutritional role. The colonic flora is capable of metabolizing nonabsorbed starch and fiber into the production of short-chain fatty acids. These short-chain fatty acids are regarded as the preferred fuel for the colon and may actually stimulate water absorption. Therefore, the residual colon may provide an opportunity to improve water absorption in patients with short bowel syndrome. [11]

Decreasing the amount of carbohydrates within the enteral feeds and decreasing the volume and concentration of feeds help manage the problems with excessive stool volume and abdominal distension in the setting of significant malabsorption. The addition of fiber can also increase stool frequency. Decreasing either the volume or rate of feeds may treat patients with gastroesophageal reflux and vomiting. The advancement of enteral feeds is based on the patient's tolerance.

Parenteral therapy

Provide parenteral nutrition to patients with massive intestinal resections as soon as possible. Increase parenteral nutrition accordingly, based on the patient's tolerance level. Before the availability of parenteral nutrition, most patients with short bowel syndrome died. The dramatic improvement in patient survival primarily is because of advances in parenteral nutrition. Today, survival has been shown in patients with as little as 11 cm of proximal small bowel and an ileocecal valve to as little as 25 cm of small bowel without an ileocecal valve. Anecdotal reports of children surviving with as little as 12 cm of bowel without an ileocecal valve are also noted. The clinical factors that are associated with prolonged (>2 y) parenteral nutritional requirements include the following:

  • Residual bowel

  • Limited absorptive function

  • Bowel adaptation (ileum has greater adaptability than jejunum)

  • Dysmotility

  • Bowel length (< 40 cm)

  • Absent ileocecal valve

  • Colon resection

  • Bacterial overgrowth

Several strategies have been proven to improve a patient's tolerance of parenteral nutrition in the setting of short bowel syndrome, including limiting the amount of toxic amino acids administered parenterally and providing protein requirements enterally with specialized infant amino acid formulas. Similarly, because enteral feeds are known to facilitate bile flow, the initiation and progression of enteral feeds may actually prevent cholestasis. Choleretic agents, such as phenobarbital and ursodeoxycholic acid, have also been shown to help treat cholestatic liver disease. Patients on long-term parenteral nutrition are at risk for central intravenous catheter infection and sepsis. Patients require aggressive home care nursing and the outpatient execution of investigations, including hematologic, biochemical, and microbiologic testing.

Moreover, these patients are at risk for intestinal bacterial translocation. Approximately 20% of all central venous catheters are removed secondary to recurrent infection. In the author's experience at the Johns Hopkins Hospital, approximately 90% of central venous catheter infections can be cleared with antibiotics alone. The role of prophylactic antibiotic therapy is controversial.

Specific nutrient requirements

Multivitamins and minerals are preferentially administered parenterally in patients with extensive small-bowel resections. In the presence of significant steatorrhea, water-soluble forms of vitamin A, vitamin E, and vitamin D are available commercially. Because calcium supplementation is important in the setting of vitamin D deficiency and malabsorption, provide supplementation enterally in order to allow for bone mineralization and growth. Regularly monitor serum calcium. Dual energy x-ray absorptiometry (DEXA) scanning may be used to monitor bone density. Because enteric bacteria synthesize vitamin K, supplementation is not necessary but can be monitored with the measurement of prothrombin time. The deficiency of water-soluble vitamins is rare.

Vitamin B-12 can be administered parenterally on a monthly basis as needed in patients with extensive ileal resections. It is also available as a nasal gel. Patients with iron deficiency secondary to either bacterial overgrowth or malabsorption should be monitored carefully and can be supplemented with intravenous iron infusions. Zinc supplements are often needed secondary to increased fecal losses. In individuals who are not on parenteral nutrition, zinc supplements can be provided in tablet form. Other micronutrients, including manganese and selenium, can be provided in pharmacologic doses as required. Although copper deficiency is rare, deficiency has been associated with anemia and cardiomyopathy. Periodic measurements of copper and selenium are merited for individuals on long-term parenteral nutrition.

Outcome

The successful nutritional management of patients with short bowel syndrome has increased long-term survival rates. The complex pathophysiology of short bowel syndrome often requires a multidisciplinary approach to patient management. Additional experience with adjunct medical and surgical therapies will potentially expand existing treatment options, thereby improving patient survival and precluding potential complications associated with long-term parenteral nutrition support.

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