The 27-year-old woman, who cannot be named for legal reasons, deliberately gave the medication to the boy to make him unwell over a period of six weeks between August and October 2015.
On several occasions, while he was treated in hospital, she contaminated intravenous tubes used to administer antibiotics with an unknown noxious substance, believed to have been faeces or sink cleaner.
She was jailed for four years and six months on Friday, after previously pleading guilty to eight charges, including administering a noxious substance to endanger life.
The woman was caught when hospital staff noticed the boy’s condition would improve during the day and worsen again in the evening when his mother was present.
His unexplained illness stopped when 24-hour nursing was introduced.
Sentencing, Judge Peter Lodder QC said: “This was repeated behaviour. It was not isolated.
“You knew that your son would have to undergo painful invasive procedures and on 29 October, what you gave your son was a potentially lethal dose.”
He acknowledged that the woman had decided to pursue the “extreme course of action” to avoid what she perceived as the “greater harm” of travelling to Syria.
But he said she could have raised her concerns with hospital staff, instead choosing to persist with making her son ill.
Judge Lodder said: “What you were inflicting on that young child threatened the very life you claim you were seeking to protect, and that must have become apparent to you.”
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