Is it obligatory for a person afflicted with chronic flatulence to clench the anal sphincter throughout ablution and prayer for fear of passing wind, or is it permissible to relax it?

The religion of Allah is ease, and He has removed hardship from His servants. If you suffer from incontinence and cannot find time for purification and prayer, then perform ablution after the time for prayer begins and pray with that ablution both obligatory and supererogatory prayers until the time for prayer ends. However, if you can find time to pray with a proper purification, then you are obliged to pray at that time. If what you are doing harms you, then it is not obligatory for you; rather, you should leave yourself as you are, for the Prophet, peace and blessings be upon him, said: "There should be no harm nor reciprocating harm." Suppressing gas is like suppressing urine and feces. If holding the muscle leads to prayer while you are suppressing gas, then it is not prescribed, for the Prophet, peace and blessings be upon him, forbade praying while suppressing the two impurities (urine and feces).