My granddaughter had reflux. That was 19 years ago. She also had food allergies and asthma. As I remember the doctor suggested alimentum because of allergies. She was allergic to milk protein. This is different than lactose intolerance. I don't remember if the alimentum helped. She also had and still has eczema and asthma. She outgrew most of the food allergies. By the time she was 7 she could drink milk. Peanuts still cause her asthma to flare up.
I do remember that what helped the reflux was to give her the bottle holding her upright. She slept fastened into her car seat because that was enough of an incline to reduce the reflux. My daughter first tried raising the head of her mattress. Didn't help because when the angle was enough to help, she slid to the bottom of her crib.
My daughter was desperate to remove the reflux and the accompanying miserable cries and lack of sleep for both of them. I've read that some think a child is in danger of SIDS sleeping in car seat. The articles said baby would fall out of it. Baby can't fall out when buckled in. The seat rested on the bare mattress. At first on the floor next to Mom's bed. My granddaughter was a couple of months old. I could see it possible for a more active child to tip it over. But that could be prevented by tying seat to crib. My granddaughter spent time in a bouncy chair and a swing both of which kept her at a helpful position. I know those are not recommended for use now. I believe that they can be used safely. There was always an adult near by who could see her when she was in them.
My daughter tried various ways to reduce spit up and reflux. Finding the right combination took time. Her pediatrician did a blood analysis for allergies. He sent her to an allergist who did skin pricks. After that my daughter eliminated some foods as she became older and was eating solid food. I think the Alumimentum helped but I don't remember to what extent.
The allergist was the most helpful. The tests showed she was allergic to milk protein, peanuts as well as other foods.
She outgrew most allergies. She drinks milk but can't eat peanuts.
If your daughter doesn't also have eczema and or asthma, what worked for my granddaughter may not be helpful. I know how difficult it is to find relief.