BC and IBS

I'm near certain I have IBS. Nearly every single thing I eat sends me to the bathroom. I take the pill and I take it 11 at night. Does it have time to digest then before I eat anything the next day? I've had light pink bleeding the second day of the last week of active pills and im worried the pill isnt digesting and I've implanted. Although, I've had similar happen in prior months and not become pregnant.