Anticoagulation After GI Bleeding Pilot Study and Registry

Inclusion Criteria: 1. Male or female subjects aged 18 years or older 2. Hospitalized with acute major non-variceal GI bleeding (defined as per ISTH criteria) while receiving OAC therapy (warfarin or DOAC). 3. OAC therapy discontinued for current acute GI bleed and not yet resumed 4. Ongoing indication for long-term anticoagulation of atrial fibrillation (moderate to high risk of stroke/systemic embolism with CHA2DS2VASc score of 3 or higher) or VTE (as per clinical care team) 5. Planned to resume DOAC post-bleed 6. At moderate to high risk of re-bleeding as per clinical care team 7. Clinical hemostasis achieved as per clinical care team 8. Able and willing to comply with follow-up examinations contained within the consent form Exclusion Criteria: 1. Mechanical heart valve 2. VTE in the context of major transient risk factor and completed 3 months of treatment 3. GI bleeding managed surgically (e.g. gastrectomy, colectomy) 4. Active or previously treated gastrointestinal cancer 5. Life expectancy from other causes of less than 3 months 6. Platelet count \< 50,000/µL (or \< 50x109/L) 7. Renal dysfunction (Creatine Clearance \<30 mL/min as calculated by the Cockcroft-Gault formula)