Pich Samnang suffers from hydrocephalus.

P ich Samnang's parents hate putting their two-year-old on public display, but say it's the only way they can raise enough money to buy him formula and medicine.

Born at their rural home 10 kilometers from Pailin, Samnang has a severe case of untreated hydrocephalus, sometimes called water on the brain, which has caused his head to swell to around three times its normal size.

He is not in pain, except when he is turned, but cannot talk, eat or coordinate his limbs.

"I feel so much pity for my son that he stays in the public in the heat and the wind," said his mother, Suon Sivorn. "It's so difficult, but we have no choice."

Samnang's parents have traveled across the country trying to cure their son, but have been told by doctors at Kantha Bopha hospital in Phnom Penh and Jayavaraman VII hospital in Siem Reap that it was too late to operate.

Chhoeurn Vuthy, pediatric surgeon at the National Pediatric Hospital, said he has seen between 30 and 40 cases of hydrocephalus in the past five years.

Hydrocephalus affects two in every 1,000 births. The most common treatment is to insert a "shunt" into the head to drain the excess cerebro spinal fluid to another part of the body where it can be better absorbed into the bloodstream.

"Before we decide to cure someone by VP Shunt, we have to diagnose thoroughly. Usually we take $180 for one patient. We do not include the cost of the shunt," said Vuthy.

Twenty of the cases Vuthy saw were diagnosed early enough to treat, but he isn't sure about post-surgery survival rates, as patients usually return to provincial areas.

In Samnang's case, Vuthy said his future depends on the thickness of his meninx, the membrane enclosing the brain.

"I cannot say how long he could live because I did not diagnose his meninx yet," said Vuthy.

Samnang's parent's have traveled as far as Kampot to seek treatment and funds for him, but have now returned to Pailin to be near their four other children.

"I ask to charity organizations, international people and especially to Prime Minister Hun Sen to help my son," said Sivorn.

"I'm concerned about his head being so large, that he won't survive until he is five," said his mother, a milestone that refers to a dream shortly after Samnang was born.

In the dream, the baby told her that they had given him the wrong name, that he would have teeth by the age of two and would speak by five.

His name was changed and he now has two small front teeth, but his parents are realistic about his chances of survival.

"If he could speak, I'd ask him, 'Samnang, what did you do in your previous life to make your head so big?'" said his father.