Recommendations for story books dealing with potty training/using toilet

[firststeps]

DS2 is 2.10 and we are in the process of potty training him. He loves stories so I wondered if anyone could recommend any good books we could read with him. TIA

There is a really great book by Tony Ross called "I want my Potty!" My dd used to love it when she was about the same age as your ds.
here

ds1 was 20 mo when we trained and loved nappy duck and potty piggy

but at the moment he thinks this one is funny (he's 2.5 yrs)

'I want my potty' is fab.