Parsing XMl with unknown tag names in C#

I am trying to parse xml to a stringbuilder in C#. But the XML file has un-determined tag names inside. I don't want to put element names by using xdoc.elements("tagName"). I wish I can dynamically loop through the XML file.

The XML I have is like this:

 <userInfo>
        <name> Gummy Bear </name>
        <age> 1 </age>
 </userInfo>

 <userInfo>
        <name> Dorito </name>
        <Email> IloveDorito@gmail.com </email>
        <hobby> eating Doritos </hobby>
 </userInfo>

As you have seen in the sample file, the only tag in common for each user is <userInfo>

The ideal output would be grouped by each user:

Gummy Bear, 1,

Dorito,IloveDorito@gmail.com,eating Doritos

I have the following code but it combines all the elements under one user into one line.

 StringBuilder result = new StringBuilder();
 XDocument xdoc = XDocument.Load(@"test.xml");
 var userNode = xdoc.Root.Elements("userInfo");
 foreach(var d in userNode)
 {
        result.append(d.value):
 }
MessageBox.show (result+"");