Final answer:
Cirrhosis predisposes to upper GI bleeding due to portal hypertension, which leads to the bypassing of the liver by portal blood. The damaged liver in cirrhosis also affects detoxification, increasing the risk of bleeding.
Step-by-step explanation:
Cirrhosis predisposes to upper GI bleeding due to several factors. The presence of scarring within the liver leads to portal hypertension, which obstructs the passage of blood through the liver. As a result, portal systemic anastomoses develop, allowing portal blood to bypass the liver and return to the heart without undergoing detoxification. Additionally, the damaged liver in cirrhosis may not function properly, leading to lower levels of detoxification. These factors increase the risk of bleeding in the upper gastrointestinal tract.