Autism 1–11 © The Author(s) 2017 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1362361316667061 journals.sagepub.com/home/aut Sleep disorders are widespread problems in children with neurodevelopmental disorders. Overall, sleep problems are more profound between the ages 2 and 6 years and decline thereafter childhood (Kothare and Kotagal, 2011). However, sleep problems tend to persevere into adulthood in individu- als with neurodevelopmental disorders and autism spectrum disorder (ASD) in particular (Kothare and Kotagal, 2011; Sivertsen et al., 2012). Frequent night arousal, difficulty ini- tiating sleep, and sleep maintenance disorder were listed among the most prevalent sleep disorders associated with ASD, with prevalence ranging from 40% to 88% (Cortesi et al., 2010; Ming and Walters, 2009; Richdale, 1999). Studies using animal models, as well as those with samples drawn from the general population, found that sleep abnor- malities were linked to an array of abnormal behaviors such as inattention, hyperactivity, and restricted/repetitive and self-injurious behaviors (Barnard and Nolan, 2008; Goldman et al., 2009; Johnson et al., 2009). Poor sleep in children with ASD further exacerbates ASD symptoms. Studies have shown that children with ASD and sleep disorders were more hyperactive and more compulsive and ritualistic in their behavior than children with ASD without sleep disorders (Cortesi et al., 2010; Goldman et al., 2009; Kothare and Kotagal, 2011). Furthermore, sleep disorders in children with ASD impact the quality of parents’ sleep increasing parental burden and family stress (Doo and Wing, 2006; Meltzer, 2008). There are several medical factors that are causally implicated in sleep disorders in ASD. These include neurological prob- lems, such as abnormalities in neurotransmitter systems (e.g. melatonin, GABA, and serotonin); medical disorders that disrupt sleep continuity (e.g. epilepsy, gastrointestinal (GI) dysfunctions, and obstructive sleep apnea); and the medications used to treat these and other co-occurring con- ditions. Some of these conditions both contribute to Gastrointestinal dysfunctions as a risk factor for sleep disorders in children with idiopathic autism spectrum disorder: A retrospective cohort study Lena M McCue, Louise H Flick, Kimberly A Twyman and Hong Xian Abstract Sleep disorders often co-occur with autism spectrum disorder. They further exacerbate autism spectrum disorder symptoms and interfere with children’s and parental quality of life. This study examines whether gastrointestinal dysfunctions increase the odds of having sleep disorders in 610 children with idiopathic autism spectrum disorder, aged 2–18 years, from the Autism Genetic Resource Exchange research program. The adjusted odds ratio for sleep disorder among those with gastrointestinal dysfunctions compared to those without was 1.74 (95% confidence interval: 1.22–2.48). In addition, the odds of having multiple sleep disorder symptoms among children with gastrointestinal dysfunctions, adjusted for age, gender, behavioral problems, bed wetting, current and past supplements, and current and past medications for autism spectrum disorder symptoms were 1.75 (95% confidence interval: 1.10–2.79) compared to children without gastrointestinal dysfunctions. Early detection and treatment of gastrointestinal dysfunctions in autism spectrum disorder may be means to reduce prevalence and severity of sleep problems and improve quality of life and developmental outcomes in this population. Keywords autism, gastrointestinal dysfunction, idiopathic autism spectrum disorder, multiplex families, severity, sleep disorder Saint Louis University, USA Corresponding author: Lena M McCue, Saint Louis University, 3545 Lafayette Ave., St. Louis, MO 63104, USA. Email: mccuel@wustl.edu 667061AUT 0 0 10.1177/1362361316667061AutismMcCue et al. research-article 2017 Original Article