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Prof. Dr. Oya Yönal Gastroenterology

Prof. Dr. Oya Yönal

✓ Medically verified profile
Gastroenterology

Prof. Dr. Oya Yönal

✓ Medically verified profile
25+ years experienceLanguages: Turkish, EnglishOnline consultationAcibadem Fulya Hospital · İstanbul
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Prof. Dr. Oya Yönal
Profile

About Prof. Dr. Oya Yönal

Quick answer

Prof. Dr. Oya Yönal is a gastroenterologist at Acibadem Fulya Hospital in İstanbul with more than 25 years of experience.

She focuses on inflammatory bowel disease, ulcerative colitis, ulcerative proctitis, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, liver fibrosis, chronic liver disease, and primary malignant melanoma of the esophagus. She consults in Turkish and English and offers online video consultations.

Prof. Oya Yönal is a gastroenterologist with specialized training in gastroenterology from Marmara University Faculty of Medicine (2010). With a clinical appointment at Acibadem Health Group since 2020, she focuses on the diagnosis and management of complex digestive diseases, including inflammatory bowel disease and liver disorders. An active member of national and international professional societies, she belongs to the Inflammatory Bowel Diseases Association, ECCO (European Crohn’s and Colitis Organization), the Turkish Association for Liver Research, and the Turkish Liver Foundation.

She also serves on the Istanbul Branch Board of the Turkish Gastroenterology Association, contributing to education, clinical standards, and professional development within the field. Her practice emphasizes evidence-based care, multidisciplinary collaboration, and patient-centered management for chronic gastrointestinal and hepatologic conditions.

Clinical Focus

Areas of Expertise

Conditions treated and procedures performed by this specialist.

Inflammatory bowel diseaseUlcerative colitisUlcerative proctitisNonalcoholic fatty liver diseaseNonalcoholic steatohepatitisLiver fibrosisChronic liver diseasePrimary malignant melanoma of the esophagus
Background

Education

  • 2010Marmara University Faculty of Medicine Gastroenterology
  • 2006Istanbul University Istanbul Faculty of Medicine Internal Medicine
  • 2001Istanbul University Faculty of Medicine
Career

Professional Experience

  • 2020Acibadem Health Group
  • 2020GelisimUniversity / Memorial Şişli Hospital / Gastroenterology / Prof. Dr.
  • 2014Memorial Sisli Hospital / Gastroenterology / Assoc. Dr.
  • 2011–2014Memorial Sisli Hospital / Gastroenterology / Specialist Dr.
  • 2007–2010Marmara University Faculty of Medicine / Gastroentereology / Research Assistant / Specialist Dr.
  • 2001–2006Istanbul University Faculty of Medicine / Internal Medicine / Research Assistant
Affiliations

Professional Memberships

  • Inflammatory Bowel Diseases Association
  • ECCO (European Crohn’s and Colitis Organization)
  • Turkish Association for Liver Research
  • Turkish Gastroenterology Association (Istanbul Branch Board Member)
  • Turkish Liver Foundation
Research

Selected Publications

  • No association between the functional cannabinoid receptor type 2 Q63R variants and inflammatory bowel disease in Turkish subiects Türk J Gastroenterol (ISI),Vol 25,639- 43pp, 2014 Yonal O, Eren F, Yilmaz Y, Atug Ö, Över HEL
  • Primary malignant melanoma of the esophagus. Case Reports in Gastroenterology (ISI), Vol. 7, 272-6 pp., 2013 Yonal O, ibrisim D, Songur Y, Cakaloglu Y, Tuncer K, Kirimlioglu H, Ozdil S.
  • Effects of sitagliptin in diabetic patients with nonalcoholic steatohepatitis Açta Gastroenterologica Belgica (ISI). Vol. 75,240-4 pp.,2012 Yilmaz Y, Yonal O, Deyneli O, Celikel CA, Kalayci C, Duman DG.
  • Should maintenance therapy be performed in ulcerative proctitis? How long should it be continued? Turkish Journal of Gas t roentero 1 ogy (ISf f Ci 11 23, 21-4 pp., 2012 Yönal O, Hatemi G, Kaymakoglu S.
  • Do anti-TNF agents and combination treatment increase pöstoperative complication risk? Turkish Journal of GastroenterologyflSD. Vol. 23, 25-9 pp., 2012 Yönal O, Hatemi G, Hamzaoğlu Ö.
  • Serum galectin-3 levels in patients with nonalcoholic fatty liver disease Clinical Biochemistry (ISI), Vol. 44, 955-8 pp.,2011 Yilmaz Y, Eren F, Kurt R, Yonal O, Polat Z, Senates E, Bacha M, Imeryuz N
  • Serum levels of soluble receptor for advanced glycation endproducts (sRAGE) are higher in ulcerative colitis and correlate with disease activity Journal of Crohn?s and Colitis aSF). Vol. 5,402-6 pp.,2011 Yilmaz Y, Yonal O, Eren F, Atug O, Över Hamzaoglu H
  • Circulating vaspin levels and epicardial adipose tissue thickness are associated with impaired coronary flow reserve in patients with nonalcoholic fatty liver disease Atherosclerosis(ISI), Vol. 217,125-9 pp.,2011 Yilmaz Y, Kurt R, Gurdal A, Alahdab YO, Yonal O, Senates E, Polat N, Eren F, Imeryuz N, Oflaz H.
  • Serum progranulin as an independent marker of liver fibrosis in patients with biopsy-proven nonalcoholic fatty liver disease Disease Markers (ISI), Vol. 31, 205-10 pp., 2011 Yilmaz Y, Eren F, Yonal O, Polat Z, Bacha M, Kurt R, Ozturk O, Avsar E.
  • Noninvasive assessment of liver fibrosis with the aspartate transaminase to platelet ratio index (APRI): Usefulness in patients with chronic liver liver disease. Hepatitis Monthlv (ISIT Vol. 11, 103-6 pp.,2011 Yilmaz Y, Yonal O, Kurt R, Bayrak M, Aktas B, Ozdogan O
Good to Know

Frequently Asked Questions

What is Dr. Oya Yönal's specialty?
Dr. Oya Yönal is a specialist in Gastroenterology at Acibadem. For a personalised assessment, the Acibadem international patient team can review your medical history and reports and explain the suitable next steps.
Which hospital does Dr. Oya Yönal practise at?
Dr. Oya Yönal sees patients at Acibadem Fulya Hospital in İstanbul. The international patient team can confirm current availability and help you plan a consultation or visit.
What languages can I use when consulting Dr. Oya Yönal?
Consultations with Dr. Oya Yönal are supported in Turkish and English. In addition, Acibadem provides multilingual coordination and interpreter support so international patients can communicate clearly throughout their care.
How can I book an appointment with Dr. Oya Yönal?
You can request an appointment with Dr. Oya Yönal using the appointment form on this page, or by contacting the Acibadem international patient team by phone or WhatsApp. After you share your details, the team checks availability and confirms your appointment, usually within 24 hours.
Is an online video consultation available with Dr. Oya Yönal?
Yes. Dr. Oya Yönal offers online video consultations, so you can discuss your condition and reports with the specialist before making any travel arrangements. The international patient team can help you schedule a secure video visit.
How many years of experience does Dr. Oya Yönal have?
Dr. Oya Yönal has around 25 years of professional experience in Gastroenterology. A summary of education, experience and professional memberships is available on this page.
Can international patients arrange treatment with Dr. Oya Yönal?
Yes. Acibadem supports international patients end to end — from the first consultation and treatment planning through appointment scheduling, interpretation during the stay and follow-up after returning home. Sharing your case for an initial assessment is free of charge.
How do I get a second opinion involving Dr. Oya Yönal?
You can request an independent review of your diagnosis and proposed treatment. Share your medical reports through the consultation or "Ask a Doctor" form on this site, and the team will arrange a specialist review and explain the available options.
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