Gastrointestinal bleeding due to whipworm (Trichuris trichiura) infestation: a case report.

Severe whipworm infestation, an exceedingly uncommon cause of gastrointestinal bleeding, has not been reported in Taiwan. The reported case concerns a 59-year-old female who had suffered from abdominal pain and passage of tarry stool for several days. Esophagogastroduodenoscopy was performed, and several roundworms were seen in the second portion of duodenum.