Daughter is 6 month old and has constipation, how can i fix that?

Constipation infant: Add sorbitol-containing juices (eg, apple, prune, or pear). If your child has already started solid foods, fruit purees can be used. Increasing fiber content of the infant’s solid foods is also recommended including multi-grain or barley cereal instead of rice cereal and pureed peas or prunes. Infrequent use of glycerin suppositories for very hard stool in the rectum.