There are several causes associated with constipation. But in children with constipation, the most common and understandable cause are lack of fiber in their diet, insufficient water intake and lack of physical activity. Yet another common cause of constipation in children is their tendency to ignore their body signs that it is time to eliminate. They may be so busy playing or watching TV that they try to withhold bowel movements. Also, some cold medicines, antacids containing aluminum and antidepressants may also cause constipation. So, in order to know if your child is constipated, here are some of the common symptoms that you should take note of: having fewer than regular bowel movements, excessive straining during a bowel movement, wetting whether day or night, abdominal pain or discomfort when passing stool, abdominal bloating, nausea, vomiting, blood on stools, tiredness and crankiness and a noticeable increases in appetite especially before or after bowel movements.