This is the answer from ayatullah sistani about my gas problem :
‘if it is possible to hold back a moment to do the ablutions and part of the prayer the precaution is to do the ablutions and the prayer in this moment but one should not redo the ablutions if he lost his ablutions during the prayer , he has to repeat only if he does something else that cancels ablution.’

So it means that if for example I feel confortable to pray , so I pray Zohr and I broke my wudhu. I can still pray asr without repeating wudhu?

No it means if you praying Zohr and break the wuzu during Namaz then you continue and you don’t need to repeat. For Asr, you have to do wuzu again if it broke during or after Zuhr.