A video EEG disclosed episodes of total body stiffening with leg abduction and crossing and intense straining with apparent discomfort, sometimes to the point of tremulousness. Because she sometimes leaked stool during her seizures, a pediatric gastroenterology consultation was requested to evaluate the problem. The history was that the episodes began shortly after the initiation of toilet training. On physical examination, there was a tubular mass in the left abdomen and the rectum was impacted with hard stool. Following evacuation of the fecal impaction and chronic therapy with stool softening agents, the child had no further episodes.
Defecation requires two coordinated events.
First, a valsalva, to increase intraabdominal pressure and second a voluntary relaxation of the pelvic floor including the external anal sphincter. Problems with defecation in childhood occur when stools are painful and a child learns to respond to defecatory urge by holding back. Instead of relaxing the pelvic floor these children contract the pelvic floor, so defecatory efforts are unsuccessful. In those cases, an increasing large fecal mass accumulates in the rectum. As a consequence, stools become even larger and harder and more painful to pass.