Meet Our Work Team

Dr Sylvia Vigh

Having a comprehensive background in all facets of gastroenterology and hepatology, Dr Sylvia Vigh is locally trained and completed her MBBS at the University of Queensland 1999. Dr Vigh undertook her physician training at the Royal Brisbane and Women's Hospital and her gastroenterology training was completed at various locations around Brisbane including the Royal Brisbane and Women's Hospital and Redcliffe Hospital.

During her training period she was exposed to all aspects of clinical, procedural and interventional gastroenterology and hepatology. Dr Vigh's particular interests include all aspects of hepatology, women's digestive health, inflammatory bowel disease and diagnostic and interventional endoscopic procedures. However she consults on any general gastroenterology condition.

Consulting and performing endoscopic procedures at the Mater Private Clinic and Mater Private Hospital Brisbane respectively, Dr Vigh also holds a Visiting Medical Officer position at Mater Adult Hospital and a teaching title of Associate Lecturer, School Of Medicine, University of Queensland.

Dr Vigh is looking forward to being of service to you and your patients and can be contacted by telephone to make an appointment or to discuss any patient management issues with you.

Dr Linus Chang

Prior to his medical studies at the University of Queensland Dr Chang completed bachelor degrees in law and commerce. He undertook his basic physician and gastroenterology training at the Princess Alexandra Hospital in Brisbane before completing his specialty training in Townsville. He has also practised throughout the United Kingdom and Singapore and completed physician training in the UK.

He completed further gastroenterology subspecialty training in endoscopic ultrasound and its role in the diagnosis and staging of upper gastrointestinal cancer at Sir Charles Gairdner Hospital in Perth, with further periods of observation and hands-on training in the Medical University of South Carolina in Charleston, USA and St Luc Hospital in Montreal, Canada.

Along with upper digestive tract malignancies, Dr Chang has special interests in diseases of the pancreas and biliary tree, Hepatitis B and high quality colonoscopy in the prevention of colorectal cancer, including colonoscopy training. He is a Senior Lecturer with the University of Queensland and teaches medical students. He is also a Royal Australasian College of Physicians supervisor to gastroenterology and basic physician trainees.

Dr Chang consults and performs procedures at the Mater campus in South Brisbane and in Sunnybank.

Dr Mazhar Haque

Dr Haque has been working at Mater since 2001. He graduated from the University of Dhaka, Bangladesh and made Queensland home soon after completing his intern year. He successfully passed all components of the Australian Medical Council (AMC) accreditation exams with high achievement.

Dr Haque completed his entire basic physician training in Queensland and undertook his advanced postgraduate training in gastroenterology at Mater and Gold Coast Hospitals. Subsequently, he spent one and a half years at Vancouver General Hospital and the University of British Columbia (UBC) Vancouver, Canada as a hepatology and liver transplant fellow.

Returning to Mater Adult Hospital as a staff specialist, Dr Haque also enjoys teaching and is heavily involved with the Mater Clinical School as a Senior Lecturer of the University of Queensland.

Dr Haque consults privately with Mater Hill Gastroenterology and has regular sessions at the Mater Private Hospital Endoscopy Unit and Sunnybank Private Hospital.

Together with general gastroenterology, colonoscopy and other endoscopic procedures, Dr Haque’s special interests are viral hepatitis and liver diseases. Dr Haque provides regular FibroscanTM sessions, a non invasive liver scan to quantify fibrosis (scarring) of the liver.

Dr Wittmann

Dr Wittmann graduated from the University of Queensland in 1994 and has been in specialist gastroenterology practice at the Mater Adult Hospital since 2004. He is a part-time staff specialist and Director of Gastroenterology at the Mater Adult Hospital and works in private practice with colleagues from the Mater Hill Gastroenterology group at the Mater Private Hospital South Brisbane campus. Dr Wittmann provides comprehensive endoscopic services including interventional ERCP, endoluminal stenting, endoscopic ultrasound, upper GI endoscopy, colonoscopy, fibroscan and general gastroenterology and hepatology consultation. His special interests include ERCP, screening colonoscopy and viral hepatitis.

Dr Wittmann sees private patients at the Mater Medical Centre (Suite 29 Level 7), 293 Vulture Street, South Brisbane Q 4101. Privately insured patients can book appointments by telephoning 3352 7552 or 3163 7820. Private referrals should be faxed to either 07 3352 7551 or 07 31631371.

Public patients and uninsured patients not able to self-fund procedures if required, should be referred to the Mater Health Services via the Mater Adult Hospital Business Referral Centre (Ph: 07 3163 6866; Fax: 07 3163 8548 using the Mater Adult Hospital Referral Form (available at