My child has suddenly started to cry non-stop after many months of improvement. What could cause this?

Various things can cause a child with autism to be chronically upset, tearful, and agitated. First, it’s important to note that failure of inulin or rifaximin to control intestinal bacterial overgrowth is rarely a cause of this. Commonly it is something causing physical stress or pain, either physically or emotionally. Chronic infections (sinus, middle ear, bladder), abdominal pain (cramping, constipation), reflux), dental issues (cavities, abscess), or emotional strain from unpleasant school or home stress. Look for these problems, and you’ll often be able to help your child to feel better.