Purpose Idiopathic pulmonary fibrosis (IPF) is an inexorably progressive disease, which has a great impact on patients' lives. Pirfenidone and nintedanib are approved and recommended antifibrotic drugs for patients with IPF. The aim of this study was to evaluate self-reported gastrointestinal side effects of antifibrotic drugs in 176 Dutch IPF patients. Methods A cross-sectional web-based anonymous survey about complaints and side effects was conducted among IPF patients in the Netherlands. Logistic regression was used to quantify whether pirfenidone and nintedanib caused complaints of nausea, vomiting, diarrhoea, appetite loss, weight loss or loss of taste or smell perception. Results The questionnaire was completed by 176 IPF patients, 71 of whom used pirfenidone and 85 nintedanib, while 20 patients did not use any antifibrotic drugs. Nintedanib users reported complaints of diarrhoea, vomiting, weight loss and loss of appetite (p <0.01). Nausea was a significant adverse reaction (p <0.05). Pirfenidone caused increased appetite loss (p <0.01) and the risk of weight loss (p <0.05). The increase in loss of appetite and weight loss did not differ significantly between the two drugs. Conclusion The current study showed that nintedanib causes a significant increase in diarrhoea, vomiting, weight loss and loss of appetite, while pirfenidone led to loss of appetite. Our results suggest new avenues regarding dietary recommendations for IPF patients.