Fructose Malabsorption is Commonly Under-diagnosed in Community Practice

Abstract

Purpose: Fructose malabsorption is under-diagnosed and unrecognized in community practice. Patient with fructose malabsorption presents with complaint similar to Irritable Bowel Syndrome (IBS). These symptoms include unexplained diarrhea, loose stool, gas/bloating, abdominal pain, cramps, nausea, etc. The symptoms are vague and non-specific. Frequently, we are obligated to obtain multiple tests to identify condition that may explain these complaints. In the past few years, we have identified many patients with fructose malabsorption using hydrogen breath analyzer. These patients often were diagnosed as IBS or chronic unexplained diarrhea. Methods: We have conducted a chart review of 179 patients who underwent hydrogen breath tests between January 2007 and December 2008. These patients were excluded from thyroid disease, celiac sprue, microscopic colitis, inflammatory bowel disease, and bacterial over-growth. The hydrogen breath tests were conducted in a sequence of glucose, fructose, and lactose. A sudden rise in breath hydrogen of 15 ppm above baseline was considered a “positive” test. Patients with “positive” glucose test were considered to have small bowel bacterial over-growth and they were excluded from data analysis. Variables recorded include age, gender, previous diagnosis, and symptom. Results: Sixty-six patients from a pool of 179 (37%) were found to have fructose malabsorption with “positive” fructose test and “negative” glucose test. Mean age for fructose malabsorption is 48 years (range 19-89). There were 15 males and 51 females. Most common symptom in male is diarrhea (80%). Most common symptom in female is bloating (76%). Most common previous diagnosis in male is chronic unexplained diarrhea (67%). Most common previous diagnosis in female were diarrhea and IBS (35%). Conclusion: Fructose malabsorption is a common condition in community practice. About 37% patients that we suspect this condition were found to have fructose malabsorption. This condition was frequently unrecognized in the past. Patients present with combination of symptoms including abdominal pain, gas/bloating, and chronic diarrhea should be offered fructose hydrogen breath test.Table: Fructose malabsorption data