Small bowel obstruction caused by anisakiasis of the small intestine: report of a case.

Enteric anisakiasis is a relatively rare disease that is difficult to diagnose preoperatively. We report a case of small bowel obstruction caused by enteric anisakiasis in a 59-year-old Japanese man who presented with abdominal pain a few hours after eating sliced, raw fish. Because of signs of an intestinal obstruction, a laparotomy was performed. Focal thickening and stenosis of the ileocecal region were seen about 100 cm from the end of the ileum and the lesion was excised. We found a moving anisakis thrusting its head into the mucosa of the excised small intestine. Histopathological examination revealed the infiltration of eosinophils in all layers of the intestinal wall and severe edema. Enteric anisakiasis is very rare, and its diagnosis is usually only made after laparotomy. Nevertheless, when signs of acute abdomen develop after the ingestion of raw fish, such as sushi or sashimi, the possibility of enteric anisakiasis should be borne in mind.