Rice Cereal Gone Horribly Wrong

The rice cereal I fed Cameron

Solids aren't going so well. Yesterday I fed Cameron less than a tablespoon of rice cereal, and about 2 hours later he projectile vomitted for 30 minutes straight--to the point of throwing up icky yellow mucus when he had nothing left to throw up.

After he was thoroughly spent, Cameron fell asleep in my arms and I sat there watching his face go pale and his lips lose color. Of course, I panicked. I called the pediatrician's office, and the nurse told me it was probably the rice cereal. She said to keep an eye on him and call back if he didn't get better by the afternoon.

For the first hour, I let him sleep in my arms so I could sob over him and make sure he was still breathing. At the start of the second hour I placed him in his swing and joined a conference call for work. Half way through the call, he woke up and, much to my relief, started nursing again. By the end of the call he was back to his alert, smiley self. What the heck?

This is actually the second time he's had this reaction. The first time was less severe and not as traumatic. I have a degree in dietetics and have taken classes in infant and child nutrition. Starting solid foods was supposed to be a cinch for me. But I don't have a clue how to proceed from here.