Alan Buchman MD, MSPH, is a professor of Clinical Surgery and Medical Director of the Intestinal Rehabilitation and Transplant Center at the University of Illinois at Chicago and director of gastroenterology at Elevance Health.

Alan Buchman, MD, MSPH

Accurately defining the population of patients with short bowel syndrome (SBS) and intestinal failure has long been a challenge in gastroenterology.

In an effort to bring greater clarity to the field, Alan Buchman MD, MSPH, a professor of Clinical Surgery and Medical Director of the Intestinal Rehabilitation and Transplant Center at the University of Illinois at Chicago and director of gastroenterology at Elevance Health, led the introduction of new, more specific ICD-10-CM codes for SBS, along with corresponding updates to World Health Organization ICD-11 classifications. His recent real-world US claims analysis presented at the ASPEN 2026 Nutrition Science and Practice Conference examined how widely those codes have been adopted and what that adoption, or lack thereof, reveals about disease burden and clinical practice.

A a condition that develops when the small intestine is shortened or damaged and cannot absorb enough nutrients from the foods you eat to maintain health, Buchman says that historically, estimates of SBS prevalence have varied widely, in part because clinicians relied on nonspecific codes such as “postoperative malabsorption,” a designation that could encompass a broad spectrum of patients, from those with minimal ileal resections and vitamin B12 deficiency to individuals with near-total small bowel loss and true intestinal failure. The lack of granularity made it nearly impossible to determine the true size and characteristics of the SBS population, including distinctions between patients with end ileostomies and those with colon in continuity, groups with differing management strategies and prognoses.

After allowing a year for uptake of the new codes, Buchman and colleagues analyzed claims data using proxy estimates derived from 29 parenteral nutrition–related codes, as well as prior malabsorption codes. They found that only about 28% of the expected patient population was identified using the new SBS-specific codes.

“What this tells us is one of two things: either the population is much smaller than what we had originally envisioned, or people are not using the new codes appropriately,” Buchman said.

He says his experience in both clinical practice and the insurance sector suggests that both undercoding and miscoding are occurring. Some patients without SBS are being assigned the new codes, while others who clearly meet criteria are not. He attributes this variability to several factors, including knowledge gaps, inconsistent documentation, and the heavy burden placed on coders who must navigate thousands of evolving codes each year.

“There's a variety of communication errors and miscommunications that probably occur, but the coding is extremely important because the only way that we can identify over a population how these patients do is to target the populations, and we've got to be able to identify the patients correctly,” he explained

Buchman notes that improved coding accuracy is not just an administrative issue. Precise identification of patients is essential for appropriate treatment selection, including use of therapies such as teduglutide (Gattex), as well as for research, clinical trial enrollment, and population-level outcomes tracking.

As code adoption improves through targeted education of both clinicians and coding professionals, the field may finally gain a clearer understanding of SBS prevalence, disease progression, and long-term outcomes.

NIDDK. Short Bowel Syndrome. April 2023. Accessed February 18, 2026. 

https://www.niddk.nih.gov/health-information/digestive-diseases/short-bowel-syndrome

Kochar B, Herfarth HH. Teduglutide for the treatment of short bowel syndrome - a safety evaluation. 

. 2018;17(7):733-739. doi:10.1080/14740338.2018.1483332

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New data show limited uptake of SBS-specific ICD-10 codes, raising concerns about misclassification and the true burden of disease.

Alan Buchman, MD, MSPH

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