Definition:
A possible cause of leaky gut is increased intestinal permeability or intestinal hyperpermeability.
That could happen when tight junctions in the gut, which control what passes through the lining of the small intestine, don't work properly. That could let substances leak into the bloodstream. People which are allergic to gluten such as with celiac disease will experience leaky gut.

Risk Factors:

Poor diet such as eating a lot of take away foods and particularly fast foods are  the main factors; consuming a lot of sugar drinks, pasta, pizza etc.

Sign and symptoms:
Bloating

Gas

Cramps

Food sensitivities and aches and pains.