"Crook in the guts," he says tersely. The picturesque reports of previously-treated and disgusted patients have left him doubtful, and he casts an anathematising eye upon the "Black Jack" bottle. "Tabloids and duty!" says the doctor, and the sufferer sighs with relief. There's no taste in tabloids, anyhow, and he reckons the doctor "ain't a bad poor something, after all!"
Source: wiktionary