My LO just started taking Zantac last night and I was wondering how long before I start seeing any improvements. I've been an emotional wreck. Right now my LO is so congested and has been chocking/gagging on her mucous more then 10 times per day. It's so scary. I see her turn bright red and struggle to breathe. I can't stand it. I'm so scared for her and feel so bad that she has to go through this pain. If your LO chokes or gags what do you do? Right now I'm picking her upright and pat her back. Any advice would be appreciated. Also, if your LO has taken Zantac, how was their experience? Did they get better?