The following are the general causes of a line in an infant’s stool to consider. First, the symptoms are caused by parasitic infections. When infants are infected with intestinal parasites, they tend to have a line in the stool, which is a symptom of the parasites being expelled from the intestines. Secondly, children with enteritis, especially bacterial enteritis, often have increased mucus in the intestines, which can also cause a line in the stool. In children, this is often accompanied by abdominal pain and even fever, which can be treated promptly with cefaclor or cefixime.