神経性食思不振症と下剤乱用に伴う酸性尿酸アンモニウム結石の2例

Abstract

症例1:21歳女.主訴は左腰部痛.中学3年から拒食があり, 神経性食思不振症と診断された.また, 発病当初から市販の下剤スルーラックを1日60～100錠, ピサコジルとして300～500mg(通常用量10mg/日)常用していた.腹部単純写真で左上部尿管に淡い結石陰影を認め, 体外衝撃波砕石術(ESWL)を3回施行し, 良好な結石片の排泄を得て退院した.その後, 左右の腎尿管結石が頻回に再発し, ESWLを9回行った.神経性食思不振症, 下剤乱用について母親から情報があり, 看護師の説得で下剤を中止し, 精神科にコンタクトをとり, 母子で定期的に受診するようになった.神経性食思不振症は改善傾向にあり, 下剤乱用, 尿路結石の再発は現在まで認めていない.症例2:18歳女.主訴は左下腹部痛.高校1年より摂食障害, 市販の下剤常用があった.点滴腎盂造影(DIP)で左腎盂の放射線透過性結石と軽度の左水腎症を認め, ESWLを施行し, 結石片の排泄をみた.細かな残石の排出が続き, DIPを併用して残石にESWLを行った.やせ著明であったことから改めて問診し, 下剤乱用と尿路結石の関連, 治療の必要性について説明する間に治療意欲が増し, 下剤は医師処方の酸化マグネシウムに限られるようになった.経過観察で結石再発はみられていない

We report two cases of urolithiasis related to anorexia nervosa and laxative abuse. Case 1: A 21-year-old woman was referred to our hospital because of left flank pain. A left ureteral stone, 10 x 6 mm in size, was successfully fragmented by extracorporeal shock-wave lithotripsy (ESWL), but she experienced repetitive formation of bilateral urinary stones and double J stent encrustation which required 13 sessions of ESWL, one session of transurethral ureterolithotripsy and one session of cystolithotripsy over a period of 5 years. All stones were comprised of pure ammonium acid urate. It was later revealed that she was diagnosed with anorexia nervosa at 15 years old and had suffered from laxative abuse (bisacodyl, 300-500 mg/day) ever since. Case 2: A 18-year-old woman was referred to our hospital because of left lower abdominal pain. A left renal stone, 15 x 10 mm in size, was successfully fragmented by ESWL, but she had double J stent encrustation which was managed by cystolithotripsy. All stones were comprised of pure ammonium acid urate. She was later diagnosed with anorexia nervosa and it turned out that she had suffered from an eating disorder and laxative abuse (bisacodyl, 200 mg/day) since the age of 15 years. Both patients had marked decrease in urine volume, hyponatremia and hypokalemia. Anorexia nervosa and laxative abuse should be suspected whenever a woman has an ammonium acid urate stone in sterile urine because the treatment of these disorders is crucial to the prevention of repetitive formation of urinary stones.