Two-year-old Zayden Tok was at his grandmother's house on the evening of Sept 22 last year when he complained of bad tummy pain.
"It was so intense that he cried out loud and his lips turned white," said his mother, Madam Tan Zilan, who was present at the time.
It was after dinner and her son was sitting in a toddler high chair watching a video. She lifted him out of the chair to pacify him. But when she tried to touch the boy's tummy, his body tensed up. "My instincts told me that I needed to take him to hospital," said the logistics executive who is in her mid-30s.
At Mount Alvernia Hospital's accident and emergency department, Madam Tan showed the doctor a photograph of her son's stools from a few weeks ago. It was purplish red and coated with mucus.
Her son had been complaining of occasional stomach pain since early September, she said.
At Mount Alvernia, a blood test found Zayden's haemoglobin level to be dangerously low at 5.1. A normal reading for children is about 12.
The doctor told Madam Tan that her son likely had been bleeding internally for some time. The boy was rushed to National University Hospital, which offers paediatric services, and he was given a blood transfusion that night.
But the worst was not over. The next morning, the boy's stools were bloody again. He underwent a series of tests and was diagnosed with Meckel's diverticulum. This is an abnormal pouch or sac in the small intestine that is present at birth.
An operation was carried out on the same day to remove the abnormal section, and again the boy was transfused with a unit of blood, said Madam Tan, whose husband is a logistics buyer in his mid-30s. Besides Zayden, they have a younger son.
Zayden was hospitalised for seven days.He is now back home "running around and playing with his favourite toys", said Madam Tan.
Referring to the health scare, she said: "It was really heartbreaking to see a two-year-old go through the blood tests, blood transfusions, scans and operation. I'm thankful that my boy was very brave.
"Not forgetting all the blood donors - without their contribution, my son wouldn't have been able to receive his blood transfusion when he needed it urgently."