Linq to Sql method return type

Question

I have a stored procedure that has

FOR XML AUTO

and I use it in a dbml file. The problem is that I want the return type to be XDocument. For now it returns the xml string cut into pieces. I can use someting like :

foreach(spMyProcedure_GetResult getResult in list)
{
    sb.Append(getResult.XML_F52E2B61_18A1_11d1_B105_00805F49916B);
}

but that seems very wrong.

I must tell you that I can not change the stored procedure. Is there a cleaner way to do this?