The goal of this prospective pragmatic randomized clinical trial is to determine if preoperative administration of tranexamic acid (TXA) reduces bleeding during and after major colorectal surgery. The primary questions are:

• Does TXA reduce bleeding during and after surgery (change in hemoglobin from before surgery to lowest value after surgery within 30 days)
• Does TXA reduce bleeding complications within 30 days of surgery (blood transfusion, return to the operating room or procedural intervention for bleeding, death due to bleeding)
• Does TXA increase the risk of thromboembolic complications within 30 days of surgery (cerebrovascular accident, myocardial infarction, deep venous thrombosis, pulmonary embolism)

Researchers will compare preoperative TXA to no TXA to answer the above questions.

Participants who receive TXA will receive 1 g TXA IV at the beginning and end of surgery in the operating room.

Inclusion Criteria:

1. Adults 18 years or older
2. Undergoing elective or non-elective inpatient abdominal and pelvic colorectal surgery

Exclusion Criteria:

1. Creatinine clearance less than 30 mL/minute
2. Long-term dialysis
3. Known defective color vision (color blind)
4. Pregnancy
5. History of venous or arterial thromboembolism, or active thromboembolic disease
6. Disseminated intravascular coagulation (DIC) - clinically suspected and/or confirmed by platelet count on CBC, fibrinogen, INR and PTT.

Pragmatic (non-blinded)