Background/AimsWeight loss is a recognized alarm symptom for organic gastrointestinal (GI) disease, yet the association between weight change (loss or gain) and specific GI symptoms remains poorly described. We assess the associations between GI symptoms and weight change in a population-based sample of Australian adults.MethodsThe prevalence of 26 GI symptoms was determined by a postal survey to 5000 residents in western Sydney, Australia (60% response rate). These were classified a priori into 5 symptom groups–abdominal pain, esophageal symptoms, dysmotility symptoms, diarrhea and constipation. Weight change was measured by two items which assessed weight loss and weight gain. Clinically relevant weight change was defined as a loss or gain of 3 or more kilograms in the past 3 months.ResultsPrevalence estimates for clinically relevant weight loss and gain in the past 3 months were 10.3% and 8.1%, respectively. When the 5 symptom groups were evaluated simultaneously, the dysmotility symptoms of fullness after meals emerged as a predictor of both weight loss (OR, 1.57; 95% CI, 1.32–1.88; P < 0.001) and weight gain (OR, 0.85; 95% CI, 0.72–0.99; P = 0.040), which also included bloating (OR, 1.64; 95% CI 1.46–1.84; P < 0.001). The associations remained significant following adjustment for socio-economic status, body mass index, and eating behaviors.ConclusionsSpecific dysmotility symptoms are independently predictive of both weight loss and weight gain. Different pathogenic mechanisms may be involved.