Is it permissible to hold back gas during prayer, or to interrupt the prayer and restart it upon feeling repeated gas after every ablution, given the presence of bloating and gas resulting from birth control pills, and suspicion of irritable bowel syndrome?

Holding back an incidental release of wind during prayer is permissible, does not invalidate ablution, and does not nullify the prayer. It is not permissible to leave the prayer except out of fear of harm from holding it back. Praying while suppressing the two most impure things (urine, feces, and wind) is disliked because it compromises khushu' (devotion and concentration). If wind occurs during prayer, there is no harm in holding it back, and the prayer is valid. There is no obligation to interrupt it or repeat it merely due to feeling wind without its actual expulsion.