During development, there is physiologic herniation of the midgut into the umbilical cord, and it then slips back in with a counterclockwise rotation. Jejunum and ileum occupy the mid abdomen and pelvis. The jejunum is involved in calcium and magnesium absorption. The ileum contains lymphoid tissue at the antimesenteric border. Small bowel infections present with a range of symptoms from diarrhea to severe dehydration to sepsis. Suspected SBO can be evaluated with plain radiography, upper GI studies, or CT. The treatment of SBO is initially nonoperative. Paralytic ileus occurs in many patients after abdominal surgery and is treated with IV fluids, nothing by mouth, and electrolyte replacement.