Swallowing Difficulty Clinical Trials

The goal of this observational study is to learn whether heterotopic gastric mucosa (HGM) in the upper esophagus is associated with swallowing difficulties (dysphagia) in adults undergoing a medically indicated gastroscopy. The main questions it aims to answer are: * Is the presence of HGM associated with dysphagia? * Is the presence of HGM associated with dyspepsia and reduced health-related quality of life? Among participants reporting dysphagia, what is the distribution of oropharyngeal versus esophageal dysphagia, and is this related to the presence of HGM? If there is a comparison group: Researchers will compare participants with endoscopically confirmed HGM to participants without HGM to determine whether dysphagia, dyspepsia symptoms, and quality-of-life measures differ between groups. Participants will: Complete pseudonymised questionnaires about dysphagia, dyspepsia symptoms, and quality of life before the gastroscopy. Undergo the medically indicated gastroscopy as planned; the endoscopist will assess whether HGM is present based on the endoscopic appearance, and routine endoscopy findings will be documented.