Question: which disorder involves the retrograde passage of infected urine
[{'answer': 'Vesicoureteral reflux ( VUR )', 'provenance': [{'wikipedia_id': '4253241', 'title': 'Vesicoureteral reflux', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 28, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Vesicoureteral reflux', 'provenance': [{'wikipedia_id': '4253241', 'title': 'Vesicoureteral reflux', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4253241', 'title': 'Vesicoureteral reflux', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 652, 'bleu_score': 0.9141903869236321, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18278842830382899474}, 'section': 'Section::::Abstract.'}]}]