Maroday in anus. In the same positions.

I have ibs since childhood sometimes loose stools sometimes constipated i got all my test done stool and urine blood cbc kft lft all were normal sometimes i feel like marood aaray hai in my  anus inside and outside jaisai kaday nechoodtay hai after washing waisai he since childhood i am feeling this problem kabhii b aatai hai and then i can't even stand or sit at that time but then it goes away in seconds I don't see any change in stool colour or any blood and then i calm down and hold my breath and i stay in the same position and then marood goes away.is it because of any sitting position which pressures my anus like Indian toilet seat we have that kind of toilet seat and i strain alot as i am constipated and i usually make rotis in the same positions.i am very worried is it serious