Introduction: The purpose of our study was to determine the role of fructose malabsorption (FM) in new patients referred to a pediatric gastroenterology service in a tertiary care center.
Methods: We conducted a retrospective chart review of patients with FM over a 47 month period (01/01/00–12/01/03) at the Children’s Hospital of Michigan. Patients diagnosed to have FM from all new patients seen during this period were reviewed. Diagnosis of FM was made by fructose breath hydrogen test (BHT); fructose dose of 1 gm/kg, up to a maximum dose of 25 gm was used. After an overnight fast, breath samples were analyzed for H2 and CH4 with a breath H2 microlyzer (Microlyzer Self-Correcting Model SC, QuinTron) at baseline and at half-hour intervals for three hours after ingesting the fructose load. H2 levels >20 ppm above baseline were considered indicative of FM. Data was reviewed regarding demographics, presenting symptoms, laboratory tests, radiology studies, endoscopies, associated conditions and response to treatment after diagnosis to a fructose-restricted diet.
Results: A total of 3476 new patients were seen by the Pediatric Gastroenterology Service during this period. Of these, 29 (M=55%, F=45%) were diagnosed with FM, making it 0.83% of patients. Mean age at diagnosis was 7 years, range 1–12 years. Distribution of ethnicity among these patients: Caucasians=72%, African-Americans=17%, Middle Eastern=3%, Hispanic=3%, Asian=3%. Recurrent abdominal pain (76%) and loose bowel movements (62%) were the most common presenting symptoms in patients with FM; others included: excessive flatus=41%, vomiting=21%, excessive burping=14%, nausea=14%, abdominal distention=10%. A fructose-rich diet was reported in 52% of the patients; the diet included excessive intake of soda, fruit juices, candy, and fruits such as apples, pears, peaches, and oranges. There was no evidence of obesity or failure to thrive in these patients. The two most concomitant conditions included GERD (48%) and lactose intolerance (LI) (24%). The response to a fructose-free diet was evaluated: Good=69%, Mild=21%, None=7%,Noncompliant=3%. Tests performed prior to diagnosis of FM included upper gastrointestinal series (14%), esophagoduodenoscopies (28%) and colonoscopies (10%). Other tests performed included: routine laboratory work (72%), extended ph monitoring (7%), and stool cultures (59%).
Conclusion: FM should be considered early in the evaluation of nonspecific GI symptoms. It is essential to obtain a comprehensive diet history from both the parent and child. FM frequently coexists with GERD and LI. Early suspicion for FM can spare the patient of other unnecessary tests.