Solitary psychosis--three cases of monosymptomatic delusion of alimentary stench treated with behavioural psychotherapy.

Three cases of monosymptomatic delusion of alimentary stench are described. Each patient was referred for behaviour therapy as a last resort, after extensive medical investigation for halitosis or flatulence and failure of other psychiatric treatment. Two of the patients showed clinical improvement after treatment, sustained at follow-up. Monosymptomatic delusion is now a treatable condition and is important to diagnosis.