OBJECTIVE:

To determine symptoms of small intestinal bacterial overgrowth (SIBO) in gastroparesis patients.

METHODS:

Patients undergoing LBT (lactulose breath test) for evaluation of SIBO were included. LBT was considered positive on the basis of three conventional criteria: (1) hydrogen level increase >20 ppm above baseline by 90 min (H2@90min); (2) dual hydrogen peaks (>10 ppm increase over baseline before second peak >20 ppm (DPHBT); and (3) breath methane increase of >20 ppm above baseline by 90 min. Results of gastric emptying scintigraphy (GES) were recorded. Patients completed the Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index.

RESULTS:

Of 740 patients who underwent LBT from December 2009 to August 2011, 471 underwent GES, with 201 having delayed GES. Of patients with delayed GES who underwent LBT 87 % were female, 23 % diabetic, 49 % used gastric acid suppressants, 29 % used opiate analgesics, 35 % used pro-motility medications, and 27 % had a history of gastrointestinal surgery. Overall, 79 (39 %) patients with gastroparesis had evidence of SIBO by LBT: 30 (15 %) had positive H2@90min, 53 (26 %) positive DPHBT, and 6 (3 %) positive breath methane test. In gastroparesis patients with positive H2@90min, there was increased severity of bloating (3.80 ± 0.20 vs 3.29 ± 0.12; P = 0.02), early satiety (3.57 ± 0.27 vs 3.05 ± 0.13; P = 0.045), and postprandial fullness (4.20 ± 0.18 vs 3.52 ± 0.12; P < 0.01) compared with negative H2@90min patients. No significant difference in symptom severity was seen between positive and negative DPHBT gastroparesis patients.

CONCLUSION:

In our cohort, 39 % of gastroparesis patients tested positive for SIBO by LBT. Positive H2@90min testing by LBT was associated with increased symptoms of bloating and excessive fullness during and after meals.