Social media has become an important communication tool in health care. Hashtags help serve as a search function, which is important given that around 500 millions posts are made on Twitter each day. A project to devise a standardized list of gastroenterology-related hashtags (hashtag ontology) has now been completed. Key stakeholders, such as professional organisations and peer-reviewed journals, were involved in reviewing the list, and it is hoped that the finalized hashtag ontology should enable patients and physicians to search and find relevant content more easily.