Have core biopsy or other minor surgical procedures within days prior to the first dose of bevacizumab Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day Patients who have had any surgical procedure, excluding central venous catheter placement or other minor procedures (e.g. skin biopsy) within days of day Minor surgical procedure (e.g., stereotactic biopsy within days of first study treatment; placement of a vascular access device within days of first study treatment). Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day of FOLFIRI + bevacizumab initiation Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to Day Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to study enrollment Patients are excluded if they have had a biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to randomization Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within calendar days prior to the first dose of bevacizumab Patients who have had any surgical procedure, excluding central venous catheter placement or other minor procedures (e.g. skin biopsy) within days of day Core biopsy or other minor surgical procedure (excluding placement of a vascular access device, paracentesis, and/or thoracentesis) within days prior to the first date of bevacizumab therapy Patients must not have experienced a core biopsy or other minor surgical procedure within days prior to registration; NOTE: this excludes placement of a vascular access device up to days prior to registration Patients who have had any surgical procedure, excluding central venous catheter placement or other minor procedures (e.g. skin biopsy) within days of day Less than days have passed from core biopsies or other minor surgical procedures excluding placement of a vascular access device Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day Care biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day ; (minor surgical procedures include minimally invasive procedures such as fine needle aspiration, core biopsy, etc. requiring little if any supportive care excluding lumbar puncture and bone marrow aspiration/biopsy) Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day Core biopsy or other minor surgical procedure, excluding placement of a vascular access device within days prior to starting drug (continued from no. ) Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to the first date of bevacizumab therapy Minor surgical procedure(s) within days of enrollment or not yet recovered from prior minor surgery (placement of central venous access device, fine needle aspiration, or endoscopic biliary stent ? day before enrollment is acceptable) Any surgical procedure, excluding central venous catheter placement, bone marrow biopsy, lumbar puncture, or other minor procedures (e.g., skin biopsy) within days of day ; patients who have undergone major surgery =< days prior to starting study drug or who have not recovered from side effects of such procedure are ineligible for the study Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to Day Patients may not have had a core biopsy, skin cancer resection, or other minor surgical procedure, including placement of a vascular access device, within days prior to Day of the protocol. Bleeding risks: Required to be on therapeutic anticoagulation (aspirin is allowed), coagulopathy (e.g. hemophilia or von Willebrand's disease); any grade III or greater hemorrhage, major surgical procedure, or significant trauma within days; core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days Core biopsy or other minor surgical procedure within days prior to study start Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to day Core biopsy or other minor surgical procedure, excluding placement of a vascular access device, within days prior to the first dose of bevacizumab or vanucizumab