Intestinal pseudo-obstruction caused by Giardia lamblia infection.

A woman in her 40s presented with malaise, nausea, reduced appetite, abdominal distention, loose stools and weight loss. Symptoms had started 6 months earlier and worsened in the last 2 weeks. CT enterography showed hypotonic dilated small bowel loops in absence of any mechanical obstruction. Endoscopic examinations including capsule endoscopy did not reveal any obstructing lesion, but a delayed small bowel transit time of the capsule. Duodenal histology revealed Marsh 3a villous atrophy. Secondary causes of intestinal pseudo-obstruction and villous atrophy were investigated. Giardia lamblia trophozoites were found in the stools and in the duodenal biopsies. The patient's symptoms quickly resolved after metronidazole treatment with complete normalisation of duodenal histology.