In light of her condition, her medical team recommended sending her abroad immediately for treatment during a media briefing on Sunday.
Speculation has been rife about Khaleda's health in the past few weeks, with some reports indicating that the 76-year-old had been suffering from liver cirrhosis, but the BNP was quick to shoot it down.
Party leaders have claimed that she is "fighting for her life" but they remained tight-lipped about her diagnosis.
Speaking to reporters about the BNP chief's condition, Prof Fakhruddin M Siddiqui, head of the medical board overseeing Khaleda's treatment, said she had experienced "massive bleeding" due to her ailment.
Although they managed to stop bleeding in Khaleda's colon for the time being, there is a risk of it happening again in future, which could prove fatal, he warned.
"She hasn't experienced any bleeding in the last 24 hours. She is stable now."
"But we fear that if she suffers from bleeding again, then we don't have the technology to stop it. In that case, the risk of death will increase,” he said.
According to the professor of medicine, there is no option but to send Khaleda abroad for further treatment.
Despite their best efforts, Khaleda's situation has left her doctors feeling "helpless", he said.
"Unless the transjugular intrahepatic portosystemic shunt (TIPS) method is applied now, there is a possibility of rebleeding in the future. There is a 50 percent chance of it happening next week and likelihood will increase to 60 percent the week after."
TIPS is a tract created within the liver using x-ray guidance to connect two veins within the liver. The centres offering the "highly technical" method of treatment are mostly based in America and Europe, according to Dr Samsul Arfin, an interventional gastroenterologist.
"I have not seen any patient go through it [TIPS] in our country. It is very difficult for us to get a patient who experiences bleeding twice or three times, to survive," he said.
Khaleda has experienced bleeding three times due to her liver disease while she is also suffering from diabetes and low haemoglobin levels, according to her doctors.
"At her age, there is a risk of heart failure. On top of all these complications, she has kidney disease, which could lead to anal failure. We don't how we can sustain [her health] unless the pressure can be reduced through TIPS," said Prof Fakhruddin.
"That is why we are recommending that she be treated abroad."