I Have Developed Bubbles In My Rectum Which Come Out

I have developed bubbles in my rectum which come out of rectum as bubbles and air. No real smell. Occurs more at nite in bed. Can not hold them in. They just burst out.
What is the cause and is there a cure
I don't drink caffeine , very little alcohol , no veggies like cabbage .
I take probiotics and vitamins.
Hope you have and answer.