Which Statement Is True Regarding Gastrointestinal Conditions in the Patient With an Autism Spectrum Disorder?

1. There is no correlation between behavioural changes in the patient with an autism spectrum disorder and gastrointestinal symptoms

3. Behavioural changes in the patient with an autism spectrum disorder are usually a manifestation of acute gastrointestinal pathologies

4. Polyethylene glycol should not be used to treat constipation in the patient with an autism spectrum disorder

2. In paediatric patients with an autism spectrum disorder, the lack of fever or right sided abdominal pain may suggest a functional cause to gastrointestinal symptoms