• Incidence of post operative venous thromboembolism events (DVT/PE) in in patients with Inflammatory Bowel Disease [ Time Frame: 3 months post operatively ]
  The primary efficacy outcome will be a composite of symptomatic proximal DVTs of the upper and lower extremities, splanchnic VTE, nonfatal PE (segmental or greater artery), and death from PE and death from any cause within 3 months following hospital discharge.
• Incidence of bleeding while undergoing treatment with oral anticoagulant or placebo. [ Time Frame: 3 months post operatively ]
  The primary safety outcome will be bleeding reported during treatment, including major bleeding, clinically relevant non-major (CRNM) bleeding, minor bleeding, and the composite of major bleeding and CRNM bleeding.

• Incidence of post operative venous thromboembolism events (DVT/PE) in in patients with Inflammatory Bowel Disease [ Time Frame: 3 months post operatively ]
  The primary efficacy outcome will be a composite of symptomatic proximal DVTs of the upper and lower extremities, nonfatal PE (segmental or greater artery), and death from PE and death from any cause within 3 months following hospital discharge.
• Incidence of bleeding while undergoing treatment with oral anticoagulant or placebo. [ Time Frame: 3 months post operatively ]
  The primary safety outcome will be bleeding reported during treatment, including major bleeding, clinically relevant non-major (CRNM) bleeding, minor bleeding, and the composite of major bleeding and CRNM bleeding.

• IBD
• Venous Thromboembolism
• Crohn Disease
• Ulcerative Colitis
• Pulmonary Embolism
• Colorectal Disorders

• Drug: Apixaban 2.5 milligram
  2.5 milligram daily dosing of Apixaban beginning on the first day of hospital discharge for a total of 30 days
• Drug: Placebo Oral Tablet
  placebo oral tablet that resembles the experimental drug. To be taken with the same frequency and duration

• Placebo Comparator: Placebo
  The placebo group will receive a similarly appearing full supply of a twice daily placebo oral tablet.
  Intervention: Drug: Placebo Oral Tablet
• Experimental: Experimental
  The treatment arm will receive a full supply of twice daily 2.5 milligram (mg) dosing of apixaban beginning on the first day of hospital discharge.
  Intervention: Drug: Apixaban 2.5 milligram

Inclusion Criteria:

• >18 years old
• Having documented pathological diagnosis of either Crohn's disease or ulcerative colitis.
• Open or laparoscopic abdominal gastrointestinal surgery
• Elective surgery
• Surgery occurring at Hamilton Health Sciences or St. Joseph's Healthcare Hamilton
• Negative urine beta-hCG for women of childbearing potential

Exclusion Criteria:

• Contraindication to use of postoperative thromboprophylaxis (ie. Previous bleeding on anticoagulation)
• Allergy to apixaban
• History of VTE
• Current clinically significant active bleeding, including GI bleeding
• Hepatic disease associated with coagulopathy and clinically relevant bleeding risk
• Severe renal impairment (eCrCl <30 ml/min), or undergoing dialysis
• Lesions or conditions at increased risk of clinically significant bleeding (e.g. recent GI bleeding, recent ischemic or hemorrhagic cerebral infarction, active ulcerative GI disease, recent brain, spinal or ophthalmological surgery, bronchiectasis or history of pulmonary bleeding, thrombocytopenia or functional platelet defects, congenital or acquired coagulation disorder)

• Receiving any of the following drugs:

  • Strong inhibitors of both CYP 3A4 and P-gp, such as azole-antimycotics (e.g. ketoconazole, itraconazole, voriconazole, or posaconazole), and HIV protease inhibitors (e.g. ritonavir)
  • Strong inducers of both CYP 3A4 and P-gp (e.g. rifampicin, phenytoin, carbamazepine, phenobarbital, or St. John's Wort)
  • Drug products affecting hemostasis (e.g. NSAIDs, ASA or other antiplatelet agents [e.g. ASA, clopidogrel, prasugrel, ticagrelor], SSRIs, or SNRIs)
  • Any other anticoagulant, including unfractionated heparin, LMWH, heparin derivatives, or oral anticoagulants (e.g. warfarin, dabigatran, rivaroxaban)
• Currently receiving therapy for any type of malignancy (e.g. colorectal, breast, lung)
• History of colorectal cancer
• Emergency surgery
• Patients with an indication for anticoagulation before surgery (atrial fibrillation, etc.)
• Enrolled in any other clinical trials or prospective studies where similar outcomes are measured
• Pregnant (i.e. positive pregnancy test and/or self-reported) and/or breastfeeding
• Women of childbearing potential unwilling/unable to participate in appropriate family planning during the treatment period