When I took the nursing bottle of my daughter, she had many episodes of constipation. We finally solved the problem with Lingonberry (Vaccinium vitis-idaea) shoots extract.
The treatment for toddlers is 25 drops (1 ml), 2 times daily with a little water between meals. The treatment lasts for up to 3 months, then take a break for 1-2 months, and you can resume.