From the Guidelines

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

The use of tranexamic acid in acute GI bleeding has been evaluated in several studies, but the evidence is not strong enough to support its routine use 1.
A large randomized placebo-controlled trial including 12,009 patients with acute upper gastrointestinal bleeding found no beneficial effect of tranexamic acid on mortality, and an increased risk of venous thromboembolic events 1.
The EASL clinical practice guidelines on prevention and management of bleeding and thrombosis in patients with cirrhosis recommend against the use of tranexamic acid in patients with cirrhosis and active variceal bleeding, and also discourage its routine use in patients with cirrhosis undergoing invasive procedures 1.
A meta-analysis of tranexamic acid therapy in non-variceal upper gastrointestinal haemorrhage found that it tends to reduce mortality in ulcer bleeding patients, but further studies are necessary before it can be recommended as routine therapy 1.

Tranexamic acid may increase the risk of venous thromboembolic events, particularly in patients with cirrhosis and suspected variceal bleeding.
The use of tranexamic acid should be considered on a case-by-case basis, and only in the context of clinical trials or when other treatment options have failed.
Standard therapy for variceal bleeding includes prompt initiation of vasoactive therapy, antibiotics, and endoscopic treatment, and correction of haemostatic abnormalities is not indicated if haemostasis is achieved with these measures 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 potential to stop gastrointestinal (GI) bleeding, with evidence suggesting it may be effective in reducing rebleeding and mortality in patients with upper GI bleeding 2, 3, 4, 5.
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 may reduce all-cause mortality in patients with upper GI bleeding, although the evidence was limited by the internal and external validity of the included trials 4.
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, with a primary outcome of death due to bleeding within 5 days of randomization 6.

TXA works by inhibiting the breakdown of fibrin clots by plasmin, which helps to reduce bleeding 6.
The safety of TXA in GI bleeding is uncertain due to the methodological weaknesses and small size of existing trials, although some studies suggest that it may not increase the risk of thromboembolic disease 4, 5.

Moderate-quality evidence suggests that TXA is superior to placebo for reducing mortality in patients with upper GI bleeding, although additional higher-quality trials are needed to confirm these findings 5.
Early administration of TXA may be recommended for treating upper GI bleeding in the emergency department, although further clarification is needed on its effects in lower GI bleeding 3.