Hi,
As always,consult your doctor for advice first;the following is for informational purpose only.
The normal dose for lactulose in treating hepatic encephalopathy is 30-45ml three to four times daily by mouth; if necessary ,hourly doses of the same may be given until a laxative effect is induced;once a laxative effect has been established,dosage should be reduced to produce 2-3 loose stools daily.
Rectal dosage mostly reserved for coma patient- dilute 300ml of lactulose in 700ml water administered via rectal enema and retained for 30-60min;may repeat every 6 hours as needed;oral therapy should replace rectal as soon as possible.
God bless.