Alimentum

My daughter was Alimentum until 18 mos. Try Enriched Rice Milk. I get it at WalMart.

Have you asked your son's doctor? That is where I would start. He may have a plan in mind. If you can't get a good answer from him/her, ask them who you should talk to about this. That is what your child's doctor is for, to give you good advice, or tell you who can.
I would start there since the rest of us are just guessing and don't know your son.
R.

When my son turned 1 I started giving him regular soy milk and he liked it, maybe you can try that.
Good luck!

There are soy milks, and juice. You just have to watch the sugar and actual juice amounts in them. You can even try a teaspoon of honey in the milk, make it sweeter, I used dark karo syrup to sweeten and help with my little one's digestion issues.

Why not try goat's, almond or coconut mlk?

Our son was on Alimentum for a long time and I was so looking forward to him getting off of it when he was around a year old mostly because of the cost. He could not tolerate anything else without spitting up (more like projectile). Someone suggested the powdered milk that you buy in the grocery store that you mix in water. I bought the individual envelopes that make a quart at a time and he did great with it! He too was fine on other diary products. I guess they just contain a smaller amount and with the other ingredients it digests differently. Good luck!

my daughter was on the ever so lovely alimentum until she was 2 yrs old because of the lactose / dairy intolerance. the ONLY thing that worked for us was adding RICE MILK into the formula slowly, ounce by ounce day by day. and soon we were just drinking straight rice milk. that was the ONLY thing that got her off that nasty formula.. and it IS nasty I KNOW that one.
I hope that this will help.. there is also ALMOND MILK at walmart in the dairy case it is like 2.86$ for a 1/2 gallon. and also lactaid the same price, try that a lil at the time and see. hope that it will help!