This study is aimed to investigate the role of long-term diet adherence on manifestations of gastroesophageal reflux disease

The role of diet in the treatment of gastroesophageal reflux disease (GERD) is still under discussion. Some studies support the evidence that specific components of food plays a role in triggering symptoms or may have an impact on reflux oesophagitis. Still, only limited data are present on the long-term real-life effects of diet and behaviour on the disease manifestations and outcomes. This specific study aims to investigate the role of diet in real-life cohort of patients in whom diagnosis of GERD is initially confirmed with the use of modern techniques (questionnaires, endoscopy, oesophageal pH-impedance recordings). To make the study possible, it is planned to form a cohort of patients with different manifestations of gastroesophageal reflux disease: non-erosive GERD (NERD), reflux-oesophagitis (EE), hypersensitive oesophagus. Each form of GERD is to be established in accordance to modern concept of GERD (i.e. Lyon consensus). In addition to standard-of-care examinations, diet assessment will be performed with the use of computer-based food frequency questionnaire (FFQ), which allows to analyse frequently used foods, food products in terms of frequency of consumption and sizes of the portions. Assessment of diet will be performed at the enrolment and than with a period of three months during three years. Based on the results, it would be possible to assess the effect of long-term adherence to diet, change of the composition of it, and perform a multifactorial statistical analysis with the consideration of other confounders: change in BMI, physical activity, smoking, concomitant medications, etc.

Inclusion Criteria:

• willingness to participate (based on the signed informed consent form);
• presence of gastroesophageal reflux disease, based on the following: a) typical symptoms, like heartburn and/or regurgitation (for primary selection, symptoms should be present at least weekly, be actual for at least 3 months prior to the enrolment, and the patient should report the history of symptoms which lasts for at least 6 months); b) previous response to the intake of proton pump inhibitors; c) data of 24-hours oesophageal pH-impedance monitoring with detected pathological gastroesophageal reflux according to the Lyon consensus definitions;

Exclusion Criteria:

• pregnant or breast-feeding females;
• abdominal or chest surgery (except appendectomy or cholecystectomy in case they are not followed by adhesive disease of the abdominal organs);
• constant use of non-steroidal anti-inflammatory agents (NSAIDs), sporadic use of NSAIDs will be allowed in case the course of treatment was discontinued at least 2 weeks prior to the enrolment, in case that constant use of NSAIDs happen to be necessary after the enrolment, the patients may continue in the study but doses, frequency and duration of treatment should be carefully documented;
• history or current evidence of cancer of any aetiology and location besides skin cancer in situ successfully treated before the enrolment;
• severe patient's conditions which may lead to misinterpretation of data, or in case of patient's enrolment may put him at risk of exacerbation of co-morbid conditions, or in cases when on discretion of the investigator patient's condition would not allow him to complete the course of the observation. These conditions include, but not limited to: heart failure (class III-IV by NYHA), uncontrolled hypertension, severe neurological disorders, decompensated liver cirrhosis (Child-Pugh B or C), severe depression or other psychological disorders;
• the patient may stop his participation in the study at any time by informing the site personal about his/her decision to withdraw the consent.

Deidentified individual participants data may be shared by request. Patients personal data (name, contacts, etc) will be blinded beforehand, according to the law.

The data will be available when the study is accomplished. They will be available for the request for 2 years after the date of the study completion

By request, when the reason for IPD sharing is reasonable and clear

The personnel involved to the assessment of outcomes (changes in diet, changes on endoscopy, changes on symptoms) will be blinded to the results of each other.