Disaccharidase testing and clinical outcomes: a retrospective study

Background The etiology of many common gastrointestinal symptoms such as abdominal pain, diarrhea, and bloating often remains elusive despite laboratory and endoscopic evaluation. Disaccharidase deficiency is often overlooked as a cause of these symptoms. Our retrospective cohort study aimed to assess the potential of disaccharidase testing in guiding treatment strategies and improving clinical outcomes in adults presenting with unexplained gastrointestinal symptoms.Methods A retrospective cohort study was conducted using records from Westchester Medical Center Health system from February 2023 through May 2024. We reviewed records of symptomatic adult patients who underwent diagnostic esophagogastroduodenoscopy and biopsy for disaccharidase testing. Exclusion criteria included patients with pancreatitis, inflammatory bowel disease, and celiac disease. Fisher’s exact test was used to determine the association between interventions and symptom improvement.Results A total of 78 patients who underwent disaccharidase testing were identified, of whom 11 met the exclusion criteria. Of the 67 remaining, 88.1% had at least one deficiency. Abnormal disaccharidase results were stratified into those with single deficiencies (74.6%), pan-disaccharidase deficiencies (11.9%), and >1 enzyme deficiencies (13.6%). Among those with abnormal disaccharidase testing results (59 patients), 57 received interventions. There was a significant association between interventions and symptom improvement (P = 0.01). Among those with normal disaccharidase testing, 4 patients (50%) noted symptom improvement, whereas among patients with abnormal results, 52 (88.1%) reported improvement. There was a significant difference between abnormal and normal disaccharidase testing results and symptom improvement (P = 0.02).Conclusion Our study demonstrates a statistically significant association between targeted treatment strategies and symptom improvement in patients with identified disaccharidase deficiencies. Given the high prevalence of disaccharidase deficiencies and their symptomatic overlap with conditions such as inflammatory bowel disease, there is a potential benefit for routine disaccharidase testing during esophagogastroduodenoscopy in patients with unexplained gastrointestinal symptoms.