Some children with autism have trouble falling asleep or require only a few hours of sleep each night to function. This can be extremely problematic for families and makes it difficult for parents who start sleeping in shifts to prevent the child from getting into trouble around the house.
Many children have problems with toileting, often related to sensory issues or actual gastrointestinal problems. A great many have diarrhea or constipation, abdominal pain, gaseousness and bloating, and in many cases foul smelling, light coloured stools. This discomfort could be the cause of poor sleep habits as many individuals suffer from reflux esophagitis.
Some children with autism are picky eaters, and their diets may be limited to a few preferred foods. This self-limiting has often been attributed to food intolerance.