See this question from the same block asking about Kawasaki syndrome (but related to hepatic encephalopathy).

Systemic ammonia absorption is prevented by the administration of lactulose, which is degraded by gut bacteria to create an acidic environment (via conversion to lactic and acetic acid) that facilitates the conversion of ammonia to ammonium, trapping it in the lumen of the bowl for subsequent excretion in the stool.

Recall that you can also give rifaximin or neomycin to decrease the levels of ammoniagenic bacteria.