  We show that every state on an interval pseudo effect algebra $E$ satisfying
some kind of the Riesz Decomposition Properties (RDP) is an integral through a
regular Borel probability measure defined on the Borel $\sigma$-algebra of a
Choquet simplex $K$. In particular, if $E$ satisfies the strongest type of
(RDP), the representing Borel probability measure can be uniquely chosen to
have its support in the set of the extreme points of $K.$
