• Assessment for the diagnosis of autism and to assess the severity of autism
• 3 clinic visits to UCSF and 7 telephone visits
• There will be blood draws and ECG
• Exclusion criteria

ADHD or other diagnoses that dominates the clinical presentation Axial study (Gut Metabolite Supplementation): 8 weeks trial of study medication or placebo for ages 13-17 with GI symptoms to evaluate the effects of this supplement, which coats irritating metabolites in the gut to attempt to reduce irritability in Autism.

• 6 clinic visits to UCSF and 3 phone visits
• Exclusion criteria : history of inflammatory bowel disease, history of diabetes, certain medications.
• There will be blood draws and ECG

• Combination of 4 clinic visits at UCSF, 4 virtual visits and one phone visit.
• There will be blood draws, ECG and testing.