Case Presentation: A 31 year old male with cystic fibrosis presents to the ER complaining of episodic, sharp, and diffuse abdominal pain associated with nausea, vomiting, and obstipation for 3 days. On physical examination, the patient’s abdomen was distended and diffusely tender to palpation, with hypoactive bowel sounds, and no palpable masses.  CT abdomen revealed multiple fluid-filled dilated loops of small bowel proximally, with tapering to normal caliber small bowel distally without a definitive transition point. Based on the overall clinical presentation and imaging, the patient was started on medical management for small bowel obstruction.  He was unable to tolerate NG tube placement, and was made NPO and started on IV fluid hydration.  He had a small bowel movement on hospital day 3, and his clinical picture began to appear more like an ileus.  He was started on an aggressive bowel regimen of polyethylene glycol, lactulose, and metoclopramide with minimal success.  After consultation with patient’s pulmonologist, the possibility of DIOS became the primary differential. DIOS is managed with oral laxatives, with progression to intestinal lavage or gastrograffin enema in refractory cases. A therapeutic gastrografin enema was performed on hospital day 6.  He remained symptomatic with continued abdominal pain, and distention until hospital day 8 when he had multiple large bowel movements and reported resolution of symptoms.

Discussion: Cystic Fibrosis (CF) is classically associated with recurrent pulmonary infections, and pancreatic insufficiency.  In addition, gastrointestinal manifestations contribute significantly to the morbidity associated with CF. Distal Intestinal Obstruction Syndrome (DIOS) is a complication of CF with an estimated to lifetime prevalence of 14-16%.  The ESPGHAN CF Working Group defines DIOS as a combination of abdominal pain and/or distention, a fecal mass in the ileo-cecum, and in its complete form, bilious vomiting and/or fluid levels in the small bowel on imaging. This case demonstrates the importance of early recognition of DIOS as potential cause of ileus in CF patients. Although DIOS typically presents more subacutely, it can rarely present with acute onset of symptoms mirroring those of small bowel obstruction. Since the management is different for these conditions, and CF patients are at high risk for malnutrition, early diagnosis is key to prevent further complications. In this case, the patient had been NPO for 8 days, and was becoming increasingly malnourished. Discussions regarding the initiation TPN in this patient were also complicated as CF patients are at high risk of infection.  Although DIOS is not a rare complication of CF, it may not be high on the differential, especially when it presents acutely as in this case. 

Conclusions: Cystic fibrosis patients represent a vulnerable population, often requiring high complexity medical decision making, therefore being able to recognize and treat DIOS early can improve patient care and satisfaction.