What is the ruling of Islamic law on performing a stomach surgery that has a 20% success rate and may cause death, knowing that it causes severe pain and hinders eating?

The surgeon is the reference point for assessing the predominant belief in the patient's safety from the dangers of surgery. If the doctor's predominant belief is that the patient will perish due to the operation, then it is not permissible to proceed with it. This is because surgery is subject to conditions, one of which is that the doctor's predominant belief is that it will succeed, such that the success rate is greater than the rate of failure and demise. Otherwise, it would be contrary to the principles of Islamic law, which prioritize the preservation of life and forbid exposing it to destruction, as stated in His Almighty's saying: "And do not throw yourselves with your own hands into destruction." The doctor's undertaking of something which he predominantly believes will lead to the patient's demise is considered a form of forbidden corruption, as stated in His Almighty's saying: "And do not cause corruption on the earth after its reformation." Therefore, it is recommended to be patient and seek other methods of treatment, while having a good opinion of Allah, relying on Him, and supplicating.