Why does fish oil make my child’s behaviors worse?

Adverse reactions such as worsening behaviors, new rash, or intestinal symptoms after taking fish oil are signs that the child may still have bacterial overgrowth. I generally stop the fish oil if this occurs and increase the potency of treatment for bacteria overgrowth (inulin-> monthly rifaximin or monthly rifaximin -> continuous rifaximin) and then reintroduce the fish oil a week or so later.