When your kid eats, the food passes from their stomach into the small intestine, where it breaks down, and its nutrients are absorbed. From here, the stool makes its way into the large intestine. This is where the remnants and water are collected before the stools are passed. This is what the normal functioning of the digestive tract looks like.

Now, while your kid experiences constipation, the stools move very slowly through the large intestine. Also, the large intestine doesn’t receive enough water, resulting in dry, hard and difficult to pass stools.

Constipation in Childhood.
An update on evaluation and management by Hippokratia, 2015 Jan-Mar