A playboy Australian doctor who joined Islamic State in 2015 has surfaced in a new propaganda video that shows him working in a hospital, holding a machinegun and telling Muslims who don't join Islamic State that they have "no self-respect".

Paediatric doctor Tareq Kamleh first appeared in an IS propaganda video in 2015, spruiking its health services and urging other Muslim health professionals to join him in the IS stronghold of Raqqa, Syria.

His sudden departure from Australia shocked colleagues at hospitals in South Australia and Queensland, who said he was a lazy doctor who would flirt with his patients and use his charm and good looks to get nurses to do his work.

On Tuesday, a fresh video surfaced online suggesting Kamleh has survived more than two years of fighting in the region and sustained air strikes by coalition forces.