5.3.5 Intestinal Obstruction
An intestinal obstruction is a partial or complete blockage in the small or large intestine that prevents forward flow of digestive products.There are two forms of intestinal obstructions.The first form is mechanical blockage，also called ileus，where contents of the intestine are prevented from moving forward due to an obstacle or barrier that blocks the lumen.The second form is nonmechanical blockage，also called paralytic ileus，where peristaltic movement is lacking or absent and contents are no longer propelled through the intestine.
Mechanical obstructions include tumors，scar tissues（adhesions），intestinal twisting（volvulus），intestinal telescoping，also called intussusceptions（part of the intestine slips into another part just beneath it），strangulated hernia in which the blood supply to the intestine or tissues is cut off，or the presence of foreign bodies，such as fruit pits and gallstones（Fig.5-4）.Nonmechanical blockages often result after abdominal surgeries or with spinal cord lesions where peristalsis or other neurogenic stimuli are affected.Other less common causes include thrombosis or embolism of mesenteric vessels and trauma or bacterial injury to the peritoneum.The clinical manifestations of an intestinal obstruction include abdominal pain and distension，nausea and vomiting，and altered bowel sounds.
Fig.5-4 Intestinal Obstructions
Diagnostic tests and procedures used to evaluate an intestinal obstruction include physical exam，blood chemistry studies，computerized tomography（CT），ultrasound，X-ray，and air or barium enema.An air or barium enema allows for enhanced imaging of the colon.During the procedure，the doctor will insert air or liquid barium into the colon through the rectum.The primary medical treatment for an intestinal obstruction is insertion of an intestinal tube.If the intestinal tube is ineffective in relieving the obstruction，surgery is indicated.(https://www.daowen.com)
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Task 7 Write a word with each of the following meanings.
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