She told the Daily Mail the experience was "terrifying", saying she feared "we were going to lose him. It didn't seem like [the doctors] were able to get him under control because they didn't know what was wrong with him."
Wardrop says she had never seen a child so sick, "and I have five children".
In just three days, Logan lost 10 per cent of his body weight and became bloated because water couldn't enter his body's cells.
He was diagnosed with adenovirus, rotavirus, salmonella poisoning and, due to the strain on his body, contracted meningitis.
While no formal testing has been conducted to establish Wardrop's claims that the shopping trolley was the source of his illness, the mother believes a process of elimination makes it the likely culprit.
"I hadn't been anywhere with him in a week so doctors advised [it was the] only place he could of gotten it," she wrote on Facebook.
The post includes grim images of her sick son and has been shared more than 12,000 times.