I am trying to define user generated polygons with Esri's ArcGIS Engine 10.1.  

Here's how it works at the moment: 

* User clicks on the map and creates points
* User connects the points

I have a collection of line segments (IPointCollection) in memory. The map looks something like this.

![enter image description here](https://i.stack.imgur.com/o9O8u.jpg)

I want to input all my line segments into an object. Then I need the object to tell me that I have 2 polygons, and one of the polygons has 5 sub polygons. 

I created a ISegmentCollection with all the segments in both polygons, then I cast the ExteriorRingBag into an IGeometryCollection, and I have my 2 main polygons. 

The bounty goes to whoever can tell me how to take the IPolygon on the left, and get it to return it's 5 sub polygons.