title: Idiopathic proximal hemimegacolon: radiologic findings and analyses of clinical and physiological characteristics.
abstract: BACKGROUND
  Idiopathic megacolon with bowel dilatation only proximal to the splenic flexure is an uncommon and poorly characterized disease. This study aimed to identify the characteristics of idiopathic proximal hemimegacolon.
  
  
  METHODS
  Five patients (2 males and 3 females) were diagnosed to have idiopathic proximal hemimegacolon and their radiologic, clinical, and physiological characteristics were reviewed. Hirschsprung's disease and other known causes of bowel dilatation were excluded by the presence of rectoanal inhibitory reflex and reviewing medical records.
  
  
  RESULTS
  Mean age at diagnosis and symptom onset were 50.4 years and 47.2 years, respectively. Four patients presented with constipation, and all five patients showed abdominal distention and abdominal pain. Four patients were successfully treated and maintained only with laxatives and prokinetics without enema. Only one patient underwent surgery for intractable constipation. Mean maximal diameters of each segment of colons measured by computed tomography were 57.5 mm, 69.3 mm, 73.0 mm, 33.3 mm, 24.0 mm, and 27.3 mm for cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum, respectively. Colon transit time was delayed in four patients with mean value of 90.0 h.
  
  
  CONCLUSIONS
  These results indicated that patients with idiopathic proximal hemimegacolon may be treated successfully only with medical therapy in most cases.
authors.affiliation: Department of Medicine, Sungkyunkwan University School of Medicine, Samsung Medical Center, Irwon-dong, Gangnam-gu, Seoul, Korea.
authors.forename: Byung-Hoon
authors.initials: BH
authors.lastname: Min
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Son
authors.forename: Jae J
authors.initials: JJ
authors.lastname: Kim
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Rhee
authors.forename: Soon Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Poong-Lyul
authors.initials: PL
authors.lastname: Rhee
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000328:Adult; D023881:Colonography, Computed Tomographic; D003248:Constipation / Q000209:etiology; D005260:Female; D005772:Gastrointestinal Transit; D006801:Humans; D008297:Male; D008365:Manometry; D008531:Megacolon / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed