Aug. 19, 2022
Short bowel syndrome (SBS) is a rare condition in which severe intestinal dysfunction prevents absorption of macronutrients and micronutrients. Adults typically develop SBS after massive surgical resection or significant damage to the small intestines. This complex condition can require a long-term or permanent need for parenteral nutrition, and lead to significant morbidity, increased health care utilization and substantially impaired quality of life.
In a review article published in The American Journal of Gastroenterology in 2022, co-authors Jamie Bering, M.D., and John K. DiBaise, M.D., describe the etiology, pathophysiology, complications and management approaches for SBS. Drs. Bering and DiBaise are gastroenterologists at Mayo Clinic's campus in Arizona.
Etiology and pathophysiology
Although the condition is rare, researchers have identified several risk factors and disorders associated with SBS. These include mesenteric ischemia, abdominal trauma, Crohn's disease, malignancy, radiation enteritis, postoperative obstructive or vascular catastrophes, and repeated abdominal surgeries. Prior abdominal surgery is a leading cause of SBS, accounting for up to 50% of cases.
A variety of clinical complications can occur in patients with SBS, including chronic diarrhea, malabsorption-related weight loss, fluid and electrolyte disturbances, micronutrient deficiencies, nephrolithiasis, and liver and kidney diseases. These complications are often associated with a loss of intestinal absorptive surface and rapid intestinal transit triggered by underlying disease, altered bowel anatomy and physiology, or treatments such as parenteral nutrition (PN) and the central venous catheter through which it is administered.
"Complications that result from SBS typically correspond to the specific regions of the gut that are missing," explains Dr. DiBaise. "And these consequences can thus help clinicians guide their approach to SBS management."
According to Drs. Bering and DiBaise, management of this condition can be complex, requiring nutritional support, fluid and electrolyte management, and pharmacologic therapies. As such, a multidisciplinary approach to management is recommended to provide optimal care.
According to Drs. DiBaise and Bering, adults with SBS should undergo a comprehensive nutritional assessment that can guide diet and fluid modifications. To maximize fluid and nutrient absorption, most patients benefit from a diet that includes complex carbohydrates, high-quality protein, sodium supplementation, and little or no simple sugars. The amount of dietary carbohydrates, fat, oxalate and fiber recommended should be tailored to each patient's intestinal anatomy. Patients with colon in continuity, for example, require a modest restriction of fat and oxalate.
Fluid and electrolytes
Because patients with SBS are at increased risk of dehydration, routine monitoring of urine output, renal function and electrolyte levels is important. Parenteral fluids (without nutrition) and oral or parenteral electrolytes may be necessary for some patients. In addition, most patients with SBS should also avoid hypertonic and hypotonic oral fluids. Oral rehydration solutions can be especially useful for patients who have an end-jejunostomy.
Several classes of medications are currently available to help manage diarrhea in patients with SBS. In their review article, Drs. DiBaise and Bering note that anti-motility and anti-secretory agents are a mainstay in SBS treatment. The authors also provide a detailed chart explaining recommendations for these medications and others, and any related considerations.
"It's important to recognize that while medications may not be readily absorbed by patients with SBS, most medications are absorbed within the proximal jejunum and can be used. Routine monitoring of medication levels in the blood, when possible, can help verify their absorption. In general, delayed-release medications should be avoided, and liquids and topical preparations and other drug delivery methods may prove to be a good alternative," explains Dr. Bering.
There has been intense interest in the development of intestinal growth factors and other agents to slow intestinal transit and thereby enhance intestinal absorption. The recent availability of a safe and effective glucagon-like peptide (GLP)-2 analogue has enhanced the treatment options described previously. This medication, administered via daily subcutaneous injections, can improve intestinal absorption and help wean parenteral support. Other longer acting
GLP-2 and GLP-1 agents that are currently in development may result in less frequent administration and improved efficacy.
Several surgical options are available to treat SBS and its related complications and improve quality of life. They include:
- Bowel continuity restoration and stoma elimination to help improve bowel function and reduce the risk of catheter-related infections
- Intestinal tapering to improve function in patients with dilated bowel
- Stricturoplasty to remove benign strictures
- Serosal patching to seal chronic fistulae that may prevent the need for resection
- Autologous gastrointestinal reconstruction procedures to increase the length of the intestine or create a reversed intestinal segment to slow transit
- Intestinal transplantation for select patients who have a lifelong dependency on PN and severe associated complications, including liver disease, loss of venous access sites, or recurrent, life-threatening episodes of central venous catheter sepsis
"Given the complexity of these patients and their management, it is important to emphasize that successful care of these patients is best accomplished by a multidisciplinary team that is experienced in the management of this syndrome," says Dr. DiBaise. To learn more, please read the review published in the American Journal of Gastroenterology.
For more information
Bering J and DiBaise JK. Short bowel syndrome in adults. American Journal of Gastroenterology. 2022;117:876.
Refer a patient to Mayo Clinic.