During pregnancy, the umbilical cord passes through a small opening in the baby's abdominal muscles. The opening normally closes just after birth. If the muscles don't join together completely in the midline of the abdomen, this weakness in the abdominal wall may cause an umbilical hernia at birth or later in life.
Ileus may also be caused by an infection inside the abdomen, such as appendicitis or diverticulitis. Disorders outside the intestine, such as kidney failure, an underactive thyroid gland, or abnormal levels of blood electrolytes (low potassium levels or high calcium levels, for example), may cause ileus.
Symptoms of ileus include, but are not limited to: 1  moderate, diffuse abdominal discomfort. 2  constipation. 3  abdominal distension.  nausea/vomiting, especially after 1  meals. vomiting of bilious fluid.  lack of bowel movement and/or 1  flatulence. excessive belching.