Teaching Case

A young adult male patient with cystic fibrosis (diagnosed at age 4 months), presenting to emergency department with abdominal discomfort, failure to pass stools a few days, unrelieved by sennoside laxatives. Two previous similar, less severe episodes one year earlier.
Unremarkable laboratory tests apart from mild elevation of c-reactive protein.

Initially, plain abdominal radiographs (Fig.1) showed gaseous dilatation of the entire small bowel with air-fluid levels suggesting obstruction. Upon further questioning, the patient admitted discontinuation of pancreatic enzymes supplements.
To support probable clinical diagnosis of distal intestinal obstruction syndrome (DIOS) and exclude other conditions, CT was requested (Fig.2): the abdominal distension was caused by diffusely dilated small bowel with air-fluid levels and fecaloid content becoming progressively dryer from the jejunum to the distal ileum. The large bowel was collapsed with some faeces only in the caecum. No signs of perforation and peritoneal effusion were seen.
Conservative management with nasogastric tube positioning, intravenous hydration, oral and enema polyethylene glycol solution allowed clinical improvement and radiographic near-complete resolution of DIOS (Fig.3) within a few days.

In patients with cystic fibrosis (CF), gastrointestinal complications represent the most important non-pulmonary manifestations, and are reportedly on the rise due to increased life expectancy. Further, they encompass acute and chronic pancreatitis, exocrine pancreatic insufficiency, meconium ileus, intussusception, constipation and distal intestinal obstruction syndrome (DIOS). The latter refers to partial or complete bowel obstruction, caused by inspissation of secretions in the bowel lumen leading to close adhesion of viscid faecal material and “sticky” mucoid intestinal content to the intestinal wall in the ileum and caecum [1-4].
DIOS may present acutely, sub-acutely or develop into a permanent condition with an intermittent course of symptoms. In adults with CF, DIOS reaches 7.4-16% lifetime prevalence, and the reported incidence falls in the range 6 to 23 episodes /1000 patients / year. Risk factors include severe genotype, pancreatic insufficiency, poorly controlled fat malabsorption, dehydration, history of meconium ileus in infancy, previous episodes of DIOS, post-organ transplantation status, diabetes, pseudomonas and Aspergillus colonisation, recurrent respiratory exacerbations [3, 5, 6].
The diagnosis is based on clinical features such as abdominal pain and distension, nausea or vomiting, and palpable faecal mass in the right lower quadrant. Albeit with limited sensitivity (63%) and specificity (33%) compared to CT, plain abdominal radiographs may confirm a diagnosis of complete versus partial bowel obstruction. As in this patient, compared to radiographs CT better depicts degree and extent of bowel dilatation, presence of air-fluid levels, and presence of impacted faeces in the small bowel and proximal colon. Furthermore, CT allows easy differentiation from intussusception and constipation, the latter characterised by gradual faecal impaction throughout the entire large bowel [1-3].
In DIOS, early recognition improves the outcome. Nowadays, conservative management is successful in 82-91% of patients. The mainstay treatment is hydration, oral administration of stool softeners such as polyethylene glycol (PEG) or sodium meglumine diatrizoate (Gastrografin). In complete obstruction with vomiting, laxatives are administered via enemas. Surgery is reserved for patients failing medical treatment [1, 3-6].