Upper GIS endoscopy named esophagogastro duodenoscopy (EGD) includes visualization of the oropharynx, esophagus, stomach, proximal duodenum, real-time evaluation, interpretation of the obtained findings ( 1 ). An EGD is indicated for the diagnostic evaluation of signs and symptoms of a wide variety of gastrointestinal disorders( 2 ). For diagnostic purpose; symptoms that include any of the following criteria; not responding to empirical therapy, associated with alarm symptoms, new-onset symptoms in a patient older than 50 years, dysphagia, odynophagia, persistent/recurrent esophageal reflux despite treatment, persistent vomiting of unknown cause, active or new upper GI bleeding and if any of the following are present, presumed chronic blood loss and iron deficiency anemia: there is clinical suspicion of an upper GI source, colonoscopy is negative and the lesion seen on upper GI tract imaging, acute caustic intake, when tissue or fluid is sampled on upper GIS tractus, in a patient with suspected small intestinal bowel disease (e.g. Celiac) and intraoperative evaluation of anatomical reconstructions. For scanning purposes; screening for dysplasia in patients with Barrett's esophagus, gastric cancer in selected patients, polyposis syndromes or upper GIS malignancies in patients with Lynch syndrome, esophageal varices in patients with portal hypertension, squamous cell carcinoma in patients with a history of caustic ingestion, to identify upper GIS pathology that may affect the treatment of other disorders (e.g. to evaluate a patient with a history of upper GI bleeding before initiation of anticoagulation). The key technical components of upper GIS endoscopy also serve as a platform on which many therapeutic interventions are based. For therapeutic purposes; bleeding treatment of upper GI tract lesions, prophylactic varicose banding, removal of foreign bodies, placement of feeding or drainage tubes, removal of selected polypoid lesions, dilatation of stenotic lesions, management of Achalasia, palliation of stenoses due to neoplasms, endoscopic treatment of intestinal metaplasia, treatment of operative complications ( 3 , 4 ).

With the prevalence of EGD, we encounter lesions of GIS more frequently and studies on this subject are very limited in our country. In this study, we retrospectively analyzed the endoscopic results of patients who applied to our outpatient clinic with GIS complaints.

The study complies with the provisions of the Declaration of Helsinki, which declares ethical principles to guide medical research. In addition, informed consent was obtained from all patients before the endoscopic procedure.

500 patients who applied to the clinics of our internal medicine and gastroenterology clinic of Abant İzzet Baysal University Medical Faculty Hospital in 2017 with GIS complaints were included in this study. Our study was designed as a cross-sectional retrospective study. EGD findings and biopsy results performed in the endoscopy unit of our hospital in 2017 were evaluated retrospectively. Patients under the age of 18 who were not admitted to our outpatient clinics due to their age and lower GIS endoscopy findings and biopsy results were not included in the study. The patients who applied to the clinics with GIS complaints were evaluated by anamnesis, physical examination, and then upper GIS endoscopic procedures included in this study.

EGD is an interventional procedure used in the diagnosis of esophageal, stomach, and duodenal diseases. It is generally accepted that many symptoms thought to be due to various benign and malignant upper gastrointestinal diseases are best evaluated by EGD. In this study, the EGD results of 500 patients in 2017 were retrospectively analyzed. 60% of the cases were female and 40% were male, and the mean age of females was 54.9±17.7 years, and the mean age of males was 53.9±17.9 years. Only 18 (3.6%) of 500 patients included in the study were found to be normal. Of the cases, 111 (22.2%) had esophageal disease, 474 (94.8%) gastric disease, 109 (21.8%) duodenal disease. These rates are 31.51% for esophageal diseases, 61.15% for gastric diseases, and 31.51% for duodenum in the Trakya University series; In the Dicle University series, 16.6% were found for esophageal diseases, 35.16% for gastric diseases, and 48.17% for duodenum. Gastric diseases were found to be more common in our study compared to other studies.

Esophagitis in 47 (9.4%) of the cases included in the study, laxity of LES in 33 (6.6%), esophageal varices in 19 (3.8%), and hiatal hernia in 18 (3.6%). Esophagitis was the most common lesion among the esophageal lesions, and laxity of LES was the second most common lesion. The incidence of esophagitis is reported between 1.23-9.4% in the literature, and it was found to be at the upper limit with 9.4% in our study ( 1 , 2 ). Gastroesophageal reflux disease (GERD) is the most common disease of the esophagus, and the most common cause of esophagitis is reflux esophagitis. Considering that esophagitis was seen in 9.4% of our cases, it turns out that GERD is a very common entity in our region. In the analysis of esophageal lesions according to age groups; The incidence of hiatal hernia and esophageal varices was found to be higher over the age of 50. (Hiatal hernia 0.6% vs 5.3% p=0.006, Esophageal varices 1.1% vs 5.3% p=0.019). The fact that Hiatal hernias are generally seen after the age of 50 suggests the wear of the structures that make up the hiatus ( 3 ). When cirrhosis is diagnosed; approximately 40% of those with compensated disease and approximately 60% of those with the decompensated disease have esophageal varices ( 4 , 5 ). The fact that esophageal varices are generally seen after the age of 50 in our study suggests that the development of varicose veins in cirrhosis is due to the complication that occurs over time after diagnosis. In our study; gastric lesions are the most common among all cases, and gastritis is the most common disease among all gastric diseases and endoscopy cases. In our country, gastritis was found to be 78% in the study conducted at Zonguldak Karaelmas University and 23% in the study conducted at Osmangazi University ( 6 , 7 ). In a study published in 2012 and conducted in Cuba, the rate of gastritis was reported as 91.6% ( 8 ). In our study, we found gastritis at a rate of 93.4%. Nutritional habits, environmental factors, and genetic differences of the relevant regions may play a role in the serious differences in gastritis rates according to cities. We think that the high rate determined in our study is because there is more than one health institution in our region, which is easier to reach the city center. Since it is relatively more difficult to reach our hospital compared to other health institutions, patients who have more serious and persistent complaints or who are considered for the endoscopic procedure after evaluating risk factors are often referred to us by a physician. We think that this may explain the high rate of gastritis in patients undergoing endoscopy in our hospital. The classification of gastritis according to the Sydney system; is aimed to give combined topographic, morphological, and etiological information as a schema ( 9 ). The most important feature of this system is the grading of changes in the gastric mucosa into five main histological features (chronic inflammation, neutrophil activity, glandular atrophy, intestinal metaplasia, and HP density) ( 10 ). In our study, we classified gastritis according to the Sydney system. Considering the endoscopic topographic distribution of gastritis according to this classification; in line with the literature, pangastritis is the most common with 74.6%, and antral lesions are seen in the second line with 18.2%. Consistent with our study, in the endoscopic topographic distribution of the study conducted in Bayburt province, pangastritis is the most common with 74.6%, and antral lesions are seen in the second line with 18.2%. When the chronicity distribution of gastritis is considered, chronic lesions are more common with 63.2%, and there is no statistically significant difference according to gender and age group (p=0.552 by gender, p=0.06 by age). Peptic ulcer disease is most commonly localized in the bulbous of the duodenum. The second most common site is the prepyloric antrum. Duodenal ulcer is more common than a gastric ulcer. In our study, by the literature, when peptic ulcers were evaluated according to their anatomical regions; the incidence of gastric ulcer was 5.2%, the incidence of the duodenal ulcer was 8.6% (2.8% of ulcers in the bulbous, 5.8% of the second part of the duodenum). A duodenal ulcer was observed more frequently than a gastric ulcer. We think that the socioeconomic level of the region, stress, inappropriate use of antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs), and excessive consumption of animal food are effective in gastritis and ulcer formation. In our study, malignancy incidence in gastric lesions was 0.5% in males, 1.3% in females, and 1% in total. In a study conducted in the Netherlands, the rate of gastric cancer was found to be 1.1%, 1.75% in Vakıf Gureba University, 6.5% in Erzurum, 2.1% in Diyarbakır, and 1.99% in Düzce in our country ( 11 – 14 ). In the 2008 data of the Turkish Ministry of Health, gastric cancer rates in females in 2006-2008 were 7.6%, 8.4%, and 8%, respectively. In our study, cancer cases were found to be lower than the ministry rates. We think that diet, regional characteristics (climate, lifestyle, etc.), lifestyle are effective in carcinogenesis. In the histological evaluation of gastric lesions; when the morphological distribution is examined, inflammation is observed in all patients (281 females, 170 males, total of 451 patients) who underwent biopsy. HP 36.6%, atrophy 10%, intestinal metaplasia 16%, dysplasia 3.2%, malignancy 1% seen as. The prevalence of HP is 10-50% in developed countries and rises to 80% in developing countries. In the study published in Japan in 2017 on the frequency of HP, the prevalence of gastric HP was found to be 6.1% ( 15 ). In a study published in our country in 2016 and conducted in Southeastern Anatolia, HP was detected in 84 (65%) of 129 patients with gastrointestinal complaints ( 16 ). The fact that the frequency of HP did not differ according to age in our study suggests that the infection was acquired at young ages, the insufficiency of treatment, and the frequency of reinfection. Intestinal metaplasia (IM) is accepted as a precursor to malignancy. While intestinal metaplasia was 16% in our study, this rate was found to be 11-48% according to the literature ( 17 ). The variation in the rates of IM within the country suggests the dietary habits at the forefront. In addition, it should be kept in mind socioeconomic and geographical conditions are also important. In the histological evaluation of gastric lesion; considering the morphological distribution by age group; the incidence of atrophy, intestinal metaplasia, and dysplasia are higher over the age of 50, and there is a statistically significant difference. This situation makes us think that the lesions leading to malignancy increase with age, and that nutritional habits and environmental factors may be effective in this situation. The incidence of ulcers in the duodenum in the cases included in our study was 8.6%, and it was 14.8% in 5306 patients in Vakıf Gureba University Internal Medicine Endoscopy Unit in our country, 1.6% in Şanlıurfa region, and 13.4% in Erzurum region ( 18 , 19 ). While the male/female ratio in duodenal ulcers was 5/1 in previous years, this ratio has decreased to 1.3/1 in recent years ( 20 ). In our study, this ratio was found to be 1.5/1. Our study has some limitations such as the retrospective nature, relatively the high rate of the female population applying to the outpatient clinics, and regarding the only one year period in 2017. In addition, patients under the age of 18 who were not admitted to our outpatient clinics due to their age and the lower GI endoscopy such as rectoscope, recto sigmoidoscopy, and total colonoscopy findings and biopsy results were not included.

Only 18 (3.6%) of 500 patients were normal. 111 (22.2%) had esophageal, 474 (94.8%) gastric, 109 (21.8%) duodenal disease. Gastritis was the most common disease among both gastric diseases and all cases undergoing endoscopy. Also, HP was seen in 165 (36.6%) of all cases. By analyzing the endoscopic lesions that are frequently seen within a year in our region via our study, we may predict that diagnostic evaluation of signs and symptoms of a wide variety of GIS disorders should be performed. Considering our study and various studies, upper GI endoscopy is generally a safe procedure for this purpose in patients presenting with various GIS complaints (21-24). Despite the rising prevalence of EGD, annual reports in the diagnostic evaluation of signs and symptoms of a wide variety of GI disorders and current related studies on this subject are very limited in our country. Hereby, we believe that our study may lead to further studies being planned in the future.