My Total Bilirubin Is 2.2 ,indirect Bilirubin Is 1.6 And

My total bilirubin is 2.2 ,indirect bilirubin is 1.6 and direct is 0.6 other SGPT and SGOT are in normal reference range, I had a stomach infection and my urine was dark just for one day in the morning na have no symptoms ,but I have IBS , last month when I did my liver test my indirect bilirubin was 1.1 and my other liver test was normal, I don’t understand why does only my indirect bilirubin increases and others remain the same Is it because of IBS or Gilbert syndrome please help me out