The safety of upper gastrointestinal endoscopic biopsy in patients receiving antithrombic drugs. A single-centre prospective observational study - Hilmi Bozkurt; Tolga Ölmez; Can Bulut; Özlem Sert; Zeynep Keklikkıran; Erdal Karaköse; Aziz Senger; Sabiye Akbulut; Erdal Polat; Mustafa Duman (Gastroenterology Review)