PATHOPHYSIOLOGY
Constipation and Encopresis
When stool passes into the rectum, distention of the walls stimulates mass peristaltic movements in the bowel. This process is called the defecation reflex. If defecation is not desired, the external sphincter contracts and voluntary retention of stool occurs. As the stool remains in the rectum, the rectum relaxes and the defecation reflex wanes. Water reabsorption from the colon continues, resulting in hard, dry stool that is difficult to pass. The eventual passage of that stool may result in pain or anal fissures. If retention of stool continues, more fissures may develop or become worse, so that eventually even soft stool may produce pain. A cycle of pain develops in which the stool is retained to avoid pain but the retention leads to even more difficult defecation. Over time, the rectum becomes enlarged. An enlarged rectum can result in failure to control the external sphincter, which in turn results in encopresis
PATHOPHYSIOLOGY
Constipation and Encopresis
When stool passes into the rectum, distention of the walls stimulates mass peristaltic movements in the bowel. This process is called the defecation reflex. If defecation is not desired, the external sphincter contracts and voluntary retention of stool occurs. As the stool remains in the rectum, the rectum relaxes and the defecation reflex wanes. Water reabsorption from the colon continues, resulting in hard, dry stool that is difficult to pass. The eventual passage of that stool may result in pain or anal fissures. If retention of stool continues, more fissures may develop or become worse, so that eventually even soft stool may produce pain. A cycle of pain develops in which the stool is retained to avoid pain but the retention leads to even more difficult defecation. Over time, the rectum becomes enlarged. An enlarged rectum can result in failure to control the external sphincter, which in turn results in encopresis
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