Gastrointestinal symptoms in bulimia nervosa: effects of treatment.

OBJECTIVES: The aim of this study was to characterize the frequency and severity of gastrointestinal symptoms in bulimic patients and to determine their response to treatment of the eating disorder.
METHODS: Forty-three consecutive bulimic patients admitted to the inpatient Eating Disorders Unit of the Psychiatry Service were asked to fill out a gastrointestinal symptoms questionnaire, an Eating Disorders Inventory, and a Zung Depression Inventory on admission and discharge. Thirty-two age- and sex-matched healthy volunteers completed the same questionnaire.
RESULTS: In bulimic patients, the most commonly reported gastrointestinal symptoms were bloating (74.4%), flatulence (74.4%), constipation (62.8%), decreased appetite (51.2%), abdominal pain (48.8%), borborygmi (48.8%), and nausea (46.5%). The average symptom score (sum of severity ratings) on the gastrointestinal symptoms questionnaire decreased from 20.6 +/- 10.8 (mean +/- SD) on admission to 13.46 +/- 10.5 (t(27) = 3.31, p < 0.01) on discharge but remained significantly higher than that of the control group (4.4 +/- 6.2, t(43) = 4.02, p < 0.001). However, the severity of reported gastrointestinal symptoms was correlated with the severity of depression (r = 0.43, p < 0.05), and when the possible mediating effects of depression on gastrointestinal symptoms were controlled statistically (analysis of covariance), the effects of treatment on gastrointestinal symptoms were not statistically significant.
CONCLUSION: Gastrointestinal symptoms in bulimics are common, multiple, and often severe and they improve with treatment. However, the most important determinant of gastrointestinal symptoms appears to be depression.