What Causes Abdominal Distention After Child Birth?

Hi, I gave birth to my baby 6 months ago, have breastfed and tried to eat healthily. I've lost weight since giving birth and now fit into my pre-pregnancy clothes, however my stomach appears to be bulging un-naturally, making me look heavily pregnant (sometimes it's worse than other times). This is a problem I had before falling pregnant and unfortunately it lead to me becoming Bulimic in a desperate attempt to get rid of the bulge. Obviously I do not want to go down that route again, I have had treatment for it and no longer feel the same urge. I'm just desperate to find out what is causing such bloating! Could it be a food type intollerance? Please help!