From the Guidelines

Tranexamic Acid (TXA) is not recommended as a primary treatment to stop a gastrointestinal (GI) bleed.

The use of tranexamic acid in acute GI bleeding has been studied, but the evidence is not strong enough to support its routine use 1.
A large randomized placebo-controlled trial found no beneficial effect of tranexamic acid in patients with acute upper gastrointestinal bleeding, and actually found an increased risk of venous thromboembolic events 1.
The British Society of Gastroenterology suggests that the use of tranexamic acid in acute lower GI bleeding should be confined to clinical trials, pending the results of the HALT-IT trial 1.
In patients with cirrhosis and active variceal bleeding, tranexamic acid is not recommended due to the lack of benefit and potential increased risk of thromboembolic events 1.
Tranexamic acid may be considered for patients with mild GI bleeding, such as those with hereditary hemorrhagic telangiectasia, but the evidence is limited and the potential for harm should be weighed against the potential benefits 1.

Tranexamic acid has been shown to reduce mortality in trauma patients, but its use in GI bleeding is not well established.
The evidence for tranexamic acid in GI bleeding is mostly based on older studies with high risk of bias.
Newer studies, such as the HALT-IT trial, are needed to determine the efficacy and safety of tranexamic acid in GI bleeding.
Other treatments, such as endoscopic therapy and acid suppression, are more effective in managing GI bleeding.

If tranexamic acid is considered, the dosage is typically 500 mg to 1000 mg orally, 3 to 4 times daily, but this may vary depending on the specific clinical context and patient factors 1.

The FDA Drug Labels for tranexamic acid (PO) do not address this question.

From the Research

Tranexamic acid (TXA) has been studied for its effectiveness in stopping gastrointestinal (GI) bleeding, with evidence suggesting it can reduce rebleeding and mortality in patients with upper GI bleeding 2, 3, 4.
A systematic review and meta-analysis of randomized controlled trials found that TXA significantly reduced the rates of continued bleeding, urgent endoscopic intervention, and mortality compared to placebo in patients with upper GI bleeding 3.
Another study found that TXA reduced the risk of death due to bleeding within 5 days of randomization, with a relative risk of 0.59 (95% CI 0.43-0.82) compared to placebo 4.

The evidence suggests that TXA does not increase the risk of thromboembolic adverse effects in patients with upper GI bleeding 2, 4.
However, the quality of evidence for some outcomes, such as the prevention of re-bleeding and the need for surgical interventions, is limited due to the risk of bias and heterogeneity among studies 4.

The effectiveness of TXA in lower GI bleeding is less clear, with some studies suggesting that further clarification is needed 3.
The HALT-IT trial, a large international randomized controlled trial, aimed to provide reliable evidence on the effects of TXA in acute upper and lower GI bleeding, but the results are not yet available in the provided evidence 5.

Based on the available evidence, TXA may be an effective medication for patients with upper GI bleeding, and early administration may be recommended for treating upper GI bleeding in the emergency department 3.
However, additional higher-quality trials are needed to confirm the efficacy and safety of TXA in GI bleeding, particularly in lower GI bleeding 4.