Best gastroenterologists in Istanbul: TOP 34 doctors

Prof. Dr. Aytaç ATAMER was born on January 31, 1964 in Adapazarı. He started his medical education at Istanbul University Istanbul Faculty of Medicine and graduated in 1987. After completing his residency training at Dicle University Faculty of Medicine, Department of Internal Medicine, Atamer worked as a specialist physician at the Social Insurance Institution (SSK) Diyarbakır Hospital. He then continued to work as a specialist physician at Diyarbakır Training and Research Hospital.

In 2008, he completed his upper specialization at Haydarpaşa Numune Training and Research Hospital Gastroenterology Clinic and in the same year, he was named Associate Professor of Internal Medicine at Haydarpaşa Numune Training and Research Hospital. In 2011, he continued his duty with the duty of establishing Yalova State Hospital Gastroenterology Clinic and compulsory service and in 2013, he became a faculty member at Yalova University. Between 2017 and 2022, he worked as a Professor at Çamlıca Erdem Hospital Gastroenterology Clinic.

Since 2022, he has been working as a Gastroenterology Specialist and Internal Medicine Specialist at NPISTANBUL Brain Hospital.

Pediatrician, Pediatric Gastroenterology and Nutrition Specialist

Education

Yeditepe University School of Medicine

Professor of Pediatrics (Chair of the Department)

2004 - 2007

Dokuz Eylül University School of Medicine

Pediatric Gastroenterology Sub-specialty

1995 – 1998

Hacettepe University School of Medicine

Pediatrics Instructor

1985 - 1987

Professional Experience

Ataşehir Florence Nightingale Hospital

Pediatrician, Pediatric Gastroenterology

2017 – Present

Kadıköy Şifa Ataşehir Hospital

Pediatric Gastroenterology and Nutrition

2013 – 2017 

Dokuz Eylül University School of Medicine

Professor of Pediatrics

1994 – 2004

Publications

Cevik N, Buyukgebiz B. Interaction between human blood group (ABO) substances and enteropathogenic

bacterial agents. Turk J Pediatr. 1987. Link

Buyukgebiz B, Ozalp I, Oran O. Investigation of serum vitamin A levels of children who had a history of

recurrent diarrhoea. J Trop Pediatrics. 1990. Link

Languages

Turkish: Native

English: Advanced

Education

MD; Hacettepe University Faculty of Medicine (2001)

Residencies

Internal Medicine; Ministry of Health Ankara Diskapi Education and Research Hospital (2009)

Pathology; Gazi University Faculty of Medicine (2004)

Fellowships

Gastroenterology and Hepatology; Necmettin Erbakan University Faculty of Medicine (2013)

Experiences

Demiroglu Bilim University Faculty of Medicine, Department of Gastroenterology and Hepatology

Istanbul Florence Nightingale Hospital (2019- currently)

Alanya Alaaddin Keykubat University Faculty of Medicine, Department of Gastroenterology and Hepatology (2017-2019)

Bundang CHA Hospital, Seoul, Korea (2018)

Konya Education and Research Hospital, Department of Gastroenterology  (2014-2017)

Certificates

Advanced Endoscopy Certificate, Bundang CHA Hospital, Seoul, Korea, 2018

Bariatric Endoscopy Certificate, Bariatric Endoscopy Global course, Sao Paulo, Brazil, 2020

Awards

2019 Rising Star, 10th Digestive Disease and Endoscopy Symposium

Memberships

Turkish Society of Internal Medicine

Turkish Society of Gastroenterology

ERCP Study Group at Turkish Society of Gastroenterology

European Society of Gastrointestinal Endoscopy

Women in Endoscopy, American Society of Gastrointestinal Endoscopy

Education

2005 – M.D., Istanbul University, Istanbul Faculty of Medicine

2010 – Internal Medicine Specialization, Haseki Training and Research Hospital

2021 – Gastroenterology Subspecialty Training, Sakarya University Faculty of Medicine

Academic & Professional Experience

Assistant Professor, Istanbul Florence Nightingale Hospital

Assistant Professor, Istanbul Bilim University Faculty of Medicine

Assistant Professor, Istanbul Yeni Yüzyıl University Faculty of Medicine

Head of Department, Giresun University Faculty of Medicine

Scientific Publications

Dr. Acar has authored over 20 international peer-reviewed articles in the fields of internal medicine and gastroenterology. Her notable contributions include studies and case reports on:

Gastrointestinal bleeding management in anticoagulant users

Rare GI cases such as bezoars, aortoesophageal fistulas, and massive hemorrhagic ascites

Liver transplantation complications, including graft-versus-host disease

The role of (pro)hepcidin in IBD-related anemia

Endoscopic interventions for acute GI bleeding

Covid-19 treatment agents and their GI implications in Turkey

(Full publication list available upon request)

Clinical Expertise

Gastrointestinal bleeding & endoscopic procedures

Hepatology & liver disease management

Inflammatory bowel diseases (IBD)

Complex GI case diagnostics

Post-transplant GI complications

Diabetic GI and cardiovascular comorbidities

EXPERIENCE*

2019 - Present, Istanbul/Istanbul/Turkey

MEMORIAL ATAŞEHİR HOSPITAL

General Surgeon

2012 - 2019, Diyarbakır/Diyarbakır/Turkey

DİCLE UNIVERSITY FACULTY OF MEDICINE

General Surgeon

2011 - 2012, Van/Van/Turkey

VAN REGIONAL TRAINING AND RESEARCH HOSPITAL

General Surgeon

2009 - 2011, Van/Van/Turkey

HAKKARİ STATE HOSPITAL

General Surgeon

2004 - 2009, Van/Van/Turkey

YÜZÜNCÜYIL UNIVERSITY FACULTY OF MEDICINE

General Surgeon

2002 - 2004, Van/Van/Turkey

HACIBEKİR HEALTH CENTER

General Practitioner

*EDUCATION*

2018 - 2019, Diyarbakır/Turkey

Associate Professor

2015, Ohio/USA

OHIO STATE UNIVERSITY WEXNER MEDICAL CENTER

Neck Dissection Training

2012 - 2018, Diyarbakır/Turkey

Assistant Professor

1996 - 2002, Adana/Turkey

ÇUKUROVA UNIVERSITY

FACULTY OF MEDICINE - Medical Doctor Education

Dr. Specialist Surgeon Rafail Ibayev is an expert in advanced gastrointestinal surgery. He specializes in both laparoscopic and open procedures for diseases of the stomach, intestine, and rectum. Dr. Ibayev is a recognized leader in obesity and metabolic surgery. He has extensive experience in sleeve gastrectomy, gastric bypass, and gastric balloon procedures. His patients achieve high success rates in weight management and metabolic health.

Dr. Ibayev is known for his work in minimally invasive surgery. He performs a wide range of laparoscopic operations that help patients recover faster and with less scarring. He is also skilled in endocrine and breast surgery, including advanced oncoplastic techniques for both benign and malignant conditions. As a gastrointestinal cancer specialist, he performs complex surgeries for liver, stomach, and colorectal tumors. He provides modern and effective oncological care.

Dr. Ibayev is highly trained in anti-reflux surgery, treatment of digestive disorders, endoscopic procedures, hernia repair, splenectomy, and proctologic surgeries. He is committed to patient-centered care and long-term health outcomes.

Assoc. Dr. Gokmen Ozturk is a General Surgery Specialist with 25 years of experience. He graduated from Bursa Uludag University Faculty of Medicine in 1994. He completed his surgical training at Okmeydanı Training and Research Hospital. Dr. Ozturk has also served as Deputy Chief Physician at Trabzon Fatih Regional Hospital.

Dr. Ozturk treats complex surgical cases, including bowel and colorectal cancer, breast cancer, liver metastasis, thyroid diseases, and obesity. He is skilled in minimally invasive and advanced surgical techniques. His approach helps improve patient outcomes and recovery. Dr. Ozturk currently works at Medipol University and Nisa Hospital. He is known for maintaining high standards of care and patient satisfaction.

UNIVERSITY

Ankara University Faculty of Medicine 

UNIVERSITY WHERE HE TAKES EXPERTISE

Göztepe Training and Research Hospital General Surgery

CONGRESSES ATTENDED

National Endoscopic Laparoscopic Surgery Congress

World Congress on Controversies to Consensus in Diabetes, Obesity and Hypertension

Bariatric and Metabolic Surgery Congress

Cerrahpaşa Surgery Meetings Turkish Bariatric Surgery Association

Medical Interests and Activities 

Hepatic Cirrhosis and Portal Hypertension 

Hepatic Cancer 

Viral Hepatitides (Chronic Hepatitis B, C and Delta Infections) 

Alcoholic Chronic Liver Disease 

Non-Alcoholic Fatty Liver Disease 

Stomach and Duodenal Ulcer 

Gastrointestinal Hemorrhage (Ulcer and Varicose Vein Bleeding) 

Functional Digestive System Disorders (Irritable Bowel Syndrome, Functional Intestinal Obstruction and Diarrhea...) 

Inflammatory Bowel Diseases (Ulcerative Colitis, Crohn’s Disease) 

Malabsorption Syndromes (Celiac Disease and Alike) 

Gastrointestinal Tract Malignancies

Education and Experience 

Liv Hospital, Ulus, Gastroenterohepatology Department (2013 ...) 

Associate Professor of Medicine, Obligatory Service at Gastroenterology, Şanlıurfa Training and Research Hospital (2010 - 2012) 

Subspecialty in Gastroenterohepatology, Department of Gastroenterohepatology, İstanbul Faculty of Medicine, İstanbul University (2004 - 2010) 

Research Fellow, Physician, Department of Internal Diseases, 

İstanbul Faculty of Medicine, İstanbul University (1992 - 1998)

Memberships 

Turkish Association For The Study of The Liver 

Turkish Society of Gastroenterology 

Inflammatory Bowel Disease Society 

Internal Diseases Specialty Association

Education

Doctor: Kilis Merkez No. 1 Health Center, 2006-2008
Assistant Doctor: Mersin University Faculty of Medicine, 2009-2013
Specialist Doctor: Bingöl Genç State Hospital, 2013-2014
Minor Assistant: Akdeniz University Faculty of Medicine, 2014-2017
Minor Specialist: Erzurum Regional Training and Research Hospital, 2017-2018
Subspecialist: Gaziosmanpaşa Training and Research Hospital, 2018-2020
Attending Specialist: Başakşehir Çam and Sakura City Hospital, 2020-2022
Associate Professor: Başakşehir Çam and Sakura City Hospital, 2023
Associate Professor: Istinye University Medicalpark Gaziosmanpaşa Hospital, 2023-2024

Scientific Memberships

Turkish Pediatric Society
Turkish Society for Pediatric Gastroenterology Hepatology and Nutrition
ESPGHAN - European Society for Pediatric Gastroenterology Hepatology and Nutrition.

Medical Intrests

• 
  -Irritable (Restless) Bowel Syndrome
• -Food allergies associated with the digestive system
• -Constipation, faecal incontinence
• -Acute and chronic diarrhoea, malabsorption
• -Chronic abdominal pain
• -Gastroesophageal reflux disease
• -Celiac disease
• -Ulcerative colitis, Crohn's disease
• -Treatment before and after liver transplantation
• -Acute and chronic pancreatitis

Education

Undergraduate Faculty of Medicine Trakya University 1995-2001
Medical Residency Internal Medicine Uludağ University 2001-2006
Subspecialty Gastroenterology Medeniyet University, Göztepe Training and Research Hospital / Gastroenterology Clinic 2007-2011

Experience

Internal Diseases
Assistant doctor Uludağ University Faculty of Medicine
Internal Diseases USA 2001-2006

Internal Diseases Specialist Şanlı Urfa Mehmet Akif İnan
Training and Research Hospital 2007
(Jul-Dec)

Gastroenterology Minor
Assistant Istanbul Medeniyet Universityniversitesi
Göztepe Training and Research Hospital
Gastroenterology Clinic 2007-2011
Gastroenterology Specialist Sivas Numune Hospital 2011-2013

Gastroenterology
Chief Resident Health Sciences University
Ümraniye Training and Research Hospital 2013-2017

Assoc. Dr.
Chief Assistant of Gastroenterology Clinic University of Health Sciences
Ümraniye Training and Research Hospital
2017-2021

Assoc. Dr.
Gastroenterology Clinic Administrative Responsible University of Health Sciences
Ümraniye Training and Research Hospital
2021-2024

Scientific Memberships
 

Turkish Society of Gastroenterology
Turkish Association of Liver Research
Gastrointestinal Endoscopy Society

Awards

Third Prize for Oral Presentation, 32nd National Gastroenterology Week, Turkish Gastroenterology Association, November 25-29, 2015. Turkish J. Gastroenterol 2015;26(suppl 1): Oral Presentation 03, S:11
Oral Presentation Third Prize. XVth Eurasian Congress of Gastroenterology and Surgery, 27 apr-01 May 2016, Antalya P:89

Education

• Graduation: Faculty of Medicine, Istanbul University, 1994
• Specialization: Internal Medicine, SBU Haseki Hospital, 1998
• Specialization: Gastroenterology, SBU Sisli Etfal Hospital, 2007
•  

Experience

• Associate Professorship SBÜ Ümraniye EAH, 2012
• Professorship SBÜ Ümraniye EAH, 2017
• Professorship Biruni University, 2023
•  

Scientific Memberships

• Turkish Gastroenterology Association
• Turkish Liver Association
• Inflammatory Bowel Diseases Association
• HEBIPA (Hepatitis Infections Union and Prophylaxis Association)
•  

Awards

• "National Scholar Award" in 2011 UEGW Stockholm for his study titled "Levofloxacin Based Sequential and Triple Therapy Compared with Standard Plus Probiotic Combination for Helicobacter Pylori Eradication".
• "Microscopic Colitis and Focal Active Colitis Coexistence in Patients with Irritable Bowel Syndrome" 3rd prize in the Poster Paper category at the 23rd National Gastroenterology Week 2006.
• "Investigation of Damage Pathways in Liver Tissue in Chronic Hepatitis B: A Comparative Proteomic Study" in the 26th issue of Turkish J. Gastroenterol in 2015.
• "Investigations of the EGF and its receptor EGFR gene variants in ulcerative colitis", 3rd prize in the Oral Presentation category at the XVth Eurasian Congress of Gastroenterology and Surgery 2016.
• 1st prize in the Oral Presentation category at the XVIth National Hepatitis Congress in 2023 with the study titled "Prospective evaluation of four-year follow-up results of Hepatitis C patients in AMATEM follow-up".

Medical Intrests

• EUS
• ERCP
• Cholangioscopy
• POEM
• Stomach Balloon
• ESD
• Colonoscopy
• Polypectomy
• Inflammatory bowel diseases
• Liver Cirrhosis
• Gastroesophagial Reflux Disease,
• Functional Diseases
• IBS
• Dyspepsia
• Motility
• Manometry
•  

Gastroenterology

Pendik Medipol University Hospital

Education

1999 Karadeniz Technical University, Gastroenterology

1997 Atatürk University, Internal Diseases Professorship

1992 Atatürk University, Internal Diseases Associated Professorship

1985 Atatürk University, Internal Diseases Specialist

1981 Atatürk University Faculty of Medicine

Publications

1- Nihat Okçu Gülçin Polat, Arif Yılmaz, Mehmet Koruk, The demographic features of gastric cancers in Erzurum(Eurasian J Med 2000; 32: 63-65)

2- An Evaluation of Upper Gastrointestinal Bleeding Cases. Clinical Sciences-Doctor.2000, - E.akarsu,N.Okçu,et Ark.Northeast Anatolia 6:4:435-438

3-N.Okçu, A.yılmaz. İ.kiki,MDonuk, C.gündoğdu, H.uzunismail. Our Diagnostic Upper Gastrointestinal Endoscopy Results. Atatürk University Medical Journal 1997,29 (2):486

4-N. Okçu, M.gündoğdu, MD onuk, İ.kiki, l.cerrahoğlu, k.yılmaz, I. çapoğlu. The Role of Misoprostol in Preventing Gastroduodenal Lesions in Patients Using Nonsteroidal Anti-Inflammatory Drugs (NSAIDs). Atatürk University Medical Journal 1997,29 (2):453-455.

5-N.Okçu, A. Öz, MD Onuk, E.Akarsu, B. Tekin, Hz Tonbul, H.Kaya. Plasma Fibronectin Levels in Chronic Active Hepatitis and Decoction of Liver Parenchymal Insufficiency and Their Relationship with Liver Functional Status. Turkish J. Gastroenterol 1995;27(4): 422-426.

6-N.Okçu, Tahir Buran, MD Onuk, A. Yılmaz, E.Akarsu, G. Akçay. Prevalence of Helicobacter Pylori in Patients with Duodenal Ulcer in Erzurum and Surrounding Area. Turkish J. Gastroenterol 1995;27(4): 447-450.

7-N.Okçu, bs awake, e. akarsu, e. bakan, z. tonbul. Importance of Carbohydrate Antigens (CA-19-9, CA-125), Carcinoembryonic Antigen (CEA) and Alkaline Phosphatase in Gastric and Colorectal Cancers. Turkish J. Gastroenterol 1995;6:467-471.

8-N. Okçu, MD Onuk, E. Akarsu, H. Doğan, C. Gündoğdu. Major Risk Factors in Patients with Hepatocellular Carcinoma in Our Region. Gastroenterology 1994;5(2):154-157

9-N.Okçu, md. Onuk, e. akarsu, h. doğan, c.gündoğdu, tahir buran. Frequency of gastric carcinoma in Erzurum region, endoscopic and histological features. Gastroenterology 1994;5(2):263-267.

10-N. Okçu, MD Onuk, Tahir Buran, E. Akarsu, MA Çiftçioğlu. Frequency of Helicobacter Pylori in Nonspecific Gastritis Cases in Erzurum Province. Gastroenterology 1994;5(2):211-213.

11-N.Okçu, MD Onuk, Ö. Ünal, E. Akarsu, L. İncesu, K. Akgöz. Diagnostic Value of Ultrasound-Guided Fine Needle Aspiration Biopsy in Intra-Abdominal Mass Lesions. Gastroenterology 1993;4(1):166-68.

12-NOkçu, md. onuk, m. polat, a. yılmaz, m. gündoğdu, m. paç. Budd-Chiari Syndrome (2 Cases). Turkish J Gastroenterhepatol 1993; 4(1):77-80.

13-N.Okçu, H. Koçak, MD Onuk, M. Gündoğdu, E. Bakan, A. Yılmaz, A. Başoğlu, A. Ateş, F.A. Paç. The Effect of Atrial Pressure Changes and Cardiac Nerves on Plasma Atrial Natriuretic Peptide (ANP) Levels. Vascular Surgery 1993; 27(2): 128-132

15-N.Okçu, MD Onuk, A.Yılmaz, M. Gündoğdu, T. Buran. Effects of Omeprozole and Ranitidine on Peptic Ulcer Healing. Doğa-Tr.J. of Medical Sciences 1992;16:657-658.

16-N. Okçu, Mr. Yiğitoğlu, B. Adam, E. Bakan. The Effect of Digixin on Plasma Atrial Natriuretic Peptic Level in Patients with Congestive Heart Failure. S.Ü. Medical Faculty Journal 1991;7(2):243-247..

17-N.Okçu, A. Yılmaz. The Effect of Histamine H2 -Receptor Antagonists in Upper Gastrointestinal System Bleeding. Endoscopy Journal 1991;2(4):17-23.

18-N.Okçu, E. Bakan, B. Adam, A. Yılmaz, Mr. Yiğitoğlu. Sex Hormones and Sex Hormone Binding Globulin Levels in Patients with Chronic Hepatitis and Liver Cirrhosis (Letter to the Editor). Nature-Tr. J. Of Medical Sciences 1991;15:1-2.

19-N.Okcu Ömer Yılmaz.Helıcobacter pylori and related gastrointestinal system diseases. Turkish Clinics JMed Sci. 2013;33(3):806-13

20-Nihat Okçu, Ömer Yılmaz, Hakan Dursun, Gülçin Polat. The relationship between dyspeptic symptoms, nutritional habits, endoscopic and histological findings (Eurasian J Med 2006; 38: 13-17)

21-Mehmet Bilici,1Nihat Okcu,1Kerim Cayir,1Ibrahim Pirim,2Salim B. Tekin,1andCemal Gundogdu3 - Distribution of HLA Tissue Groups in Patients with Gastric Cancer Eurasian J Med. 2010 Apr; 42(1): 9.11.

22-Nihat Okcu,Abdulhalim Bak,Mehmet Sari,Mehmet Arslan,Sait Kapicioglu:The fibroblast proliferation, relationship of hepatocyte growth factor (HGF) and interferon-A2A Gastroenterology April 2000Volume 118,Issue 4, Part 2, PageA1404

23-Kubra Kaynar,Sait Kapicioglu,Mehmet Sari,Nihat Okcu,Abdulhalim Baki. The effect of fish oil on stress ulcer prophylaxis GastroenterologyVolume 118, Issue 4, Part 2, PageA1255