Amy Marzolino watches her toddler, August, like a hawk, and with good reason.

"I'm the mom who's running across the playground when somebody hands him a goldfish and I'm reacting as though it's a handgun or something. And I look crazy," said Marzolino. But, this kind of vigilance is a "necessary evil," as she calls it. August has a dangerous condition called FPIES: Food Protein-Induced Enterocolitis Syndrome. "What it boils down to is his body not accepting food, so he can't eat," explained Marzolino.

It's a rare, and very severe type of food allergy.

Marzolino and her husband found out when August was about six months old. At that point, they already knew he had some food intolerance issues. "He was diagnosed with milk and soy protein intolerance," she recalled. But when August started to show an interest in food, they gave him some pureed carrots, and he got very sick.

"He looked pale, and wasn't making eye contact with me. And then he just opened his mouth and started vomiting. Over the course of the next couple of hours, he continued to vomit," said Marzolino.

He had diarrhea. And it took him a couple of days to recover from it.

He was diagnosed soon after this incident. Marzolino says he reacts to pretty much everything under the sun. "He reacts to tap water. We give him spring water, and if he goes in the pool, if he drinks any water with the chlorine he'll react to that."

August drinks prepared formulas that give him most of his nutrition. He can eat apples - and he eats lots of them. He can eat pears.

"And he can eat beef that we sourced from a butcher whose cows are not supplemented with soy," said Marzolino.

Despite all of his trials, August is a sweet and funny toddler with a big smile on his face. He enjoys playing with puzzles and Play-Doh- and as long as he doesn't get any in his mouth, all is well.

August is almost three now, and Marzolino says the older he gets, the less time he spends being sick. "But I would say the first year of his life he was so sick that his hands were curled in toward his stomach. And he developed torticollis, because he was in so much pain. His head was turned all the time to try and guard himself against the belly pain."

She says her son is incredibly resilient. "His personality is great. He's generally a very happy guy, and I think now that we've identified what things cause him pain, if we're careful, we can keep him comfortable."

There is a chance August will outgrow FPIES. Some kids seem to start getting better at the age of three, it's not clear why. Others have to continue living on a very limited diet.

Marzolino has tears in her eyes as she tries to envision her son's future.

"You know I hope one day he can eat. I hope he can grow up without carrying the worry that I have for him about things that are completely normal and fun."

She hopes her son can eventually enjoy the little joys that make life fun and sweet. "Like having a birthday cake. I'd really like to get him a birthday cake."