Categorize as stable versus unstable using shock index (HR/SBP), SI <1 stable, >1 unstable or suspect active bleeding
Unstable patients resuscitate, CT angiogram, if CTA does not identify source of bleeding, upper endoscopy if hemodynamic instability 
Stable calculate risk score
Oakland score
Glasgow-Blatchford score
IVF
Consider transfusing pRBCs/platelets for unstable patients or with very low hemoglobin (<7).  with cardiovascular disease use trigger of 8 and target of 10 hemoglobin.
Consider NGT - high possibility for surgery to request
Emergent sigmoidoscopy/colonoscopy (next 24 hours)
Surgery if endoscopy fails or not available
Oakland score
Glasgow-Blatchford score
Correct coagulopathy
Vitamin K 10mg IV (best bioavailability in critical patient)
PCC or FFP
Vitamin K 10mg IV (best bioavailability in critical patient)
PCC or FFP
Diverticulosis
Upper GI Bleeding
Ischemic colitis
Diverticular disease
Ulcerative colitis
Stercoral colitis
Diverticulitis
Anal fistula