Medications for Lower Gastrointestinal Bleeding
Lower GI bleeding management is primarily supportive with resuscitation and endoscopic intervention; there are no specific pharmacologic agents proven to stop lower GI bleeding, unlike upper GI bleeding where proton pump inhibitors are effective. 1, 2, 3
Resuscitation and Blood Product Management
Restrictive transfusion strategies should be employed as the primary "medication" approach:
Target hemoglobin of 7 g/dL as the transfusion trigger in hemodynamically stable patients without cardiovascular disease, with a post-transfusion goal of 7-9 g/dL. 1, 3
For patients with cardiovascular disease, use a higher threshold of 8 g/dL trigger with a target of ≥10 g/dL. 1, 4, 3
This restrictive approach has been shown to reduce mortality and rebleeding rates compared to liberal transfusion strategies. 1
Anticoagulation Reversal (When Applicable)
For patients on warfarin with severe or unstable hemorrhage:
Administer four-factor prothrombin complex concentrate (PCC) plus intravenous vitamin K 5-10 mg immediately. 4, 3
If PCC is unavailable, use fresh frozen plasma as an alternative. 4, 3
Warfarin should be interrupted at presentation for all patients with lower GI bleeding. 1, 4
For patients on direct oral anticoagulants (DOACs):
Simply withhold the medication; no reversal agent is routinely recommended. 1, 4, 3
The anticoagulant effect dissipates as the drug is metabolized. 1
For patients on unfractionated heparin:
Discontinuation alone is usually adequate due to short half-life. 1, 4
In severe life-threatening hemorrhage, reverse with protamine sulfate. 1, 4
Antiplatelet Management
Aspirin for secondary cardiovascular prevention should NOT be stopped:
If aspirin is withheld, restart it within 5 days or as soon as hemostasis is achieved. 1, 3
This recommendation is based on moderate quality evidence showing worse cardiovascular outcomes when aspirin is discontinued. 1, 3
For dual antiplatelet therapy (aspirin + P2Y12 inhibitor):
Continue aspirin; the P2Y12 inhibitor can be temporarily interrupted based on bleeding severity. 3
Restart the P2Y12 inhibitor within 5 days if still indicated. 1, 3
Aspirin for primary prevention should be permanently discontinued. 1
Specific Medications for Radiation Proctitis
For bleeding secondary to radiation proctitis (a specific lower GI bleeding etiology):
Sucralfate enemas can be used, supported by a randomized controlled trial showing benefit. 1
Sucralfate stimulates epithelial healing and forms a protective barrier over damaged mucosa. 1
Formalin enemas (3.6-4% solution) provide chemical cauterization of bleeding telangiectasias. 1
Formalin scleroses fragile neovasculature in radiation-damaged tissues. 1
What NOT to Use
Proton pump inhibitors have NO role in lower GI bleeding management:
PPIs are only effective for upper GI bleeding from peptic ulcers. 5
The lower GI tract's neutral pH makes acid suppression irrelevant. 5
Vasoactive drugs (octreotide, somatostatin) are NOT indicated:
These agents are reserved for variceal bleeding from portal hypertension, which is an upper GI source. 1
There is no evidence supporting their use in lower GI bleeding. 1
Anticoagulation Resumption Timing
For warfarin in low thrombotic risk patients:
Starting before 7 days doubles rebleeding risk without reducing thromboembolism. 1
For high thrombotic risk patients (prosthetic mitral valve, AF with prosthetic valve):
Consider low molecular weight heparin bridging at 48 hours after hemostasis. 1, 4
This applies to patients who cannot tolerate prolonged periods without anticoagulation. 1
Critical Pitfalls to Avoid
Do not delay endoscopy to administer unproven pharmacologic therapies. 5
Always exclude an upper GI source first, as 10-15% of severe hematochezia originates above the ligament of Treitz. 1, 6, 2
Do not over-transfuse; restrictive strategies improve outcomes. 1, 3
Do not routinely give PCC for DOAC-associated bleeding; simple drug discontinuation suffices in most cases. 4