I bought Organic Similac thinking it was an a safer, organic alternative to the regular Similac we had been using. But within 48 hours my son become constipated. I couldn't understand why -- he had been fine on both enfamil and similac. I did some research and disovered organic similac is made with sucrose instead of lactose, because organic lactose is really really expensive. The sucrose is basically cane syrup, which is really sweet and hard for babies to digest. Organic Similac is the ONLY formula I have found that uses sucrose. Even the knock-off walmart brand is better and contains the...