Is it obligatory to repeat the prayers after a slight discharge of gas during ablution, knowing that the discharge of gas is continuous and sometimes intermittent?

If you are not certain about the emission of an impurity before the prayer, then you are not required to repeat it, because an impurity is attributed to the most recent of its two possible times. However, if the emission of wind is continuous, then your ruling is that of one afflicted with perpetual discharge: you perform ablution after the time for prayer begins, and what is emitted thereafter does not harm you. Therefore, you are absolved from any obligation to repeat prayers if the situation is as described.