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Three Part Question

In [children with suspected intussusception] is a [negative fecal occult blood stool test sufficiently sensitive] to [rule out intussusception]?

Clinical Scenario

It is Friday evening and a 2-year-old child presents to the ED with colicky abdominal pain. The ultrasound technician has left for the evening and no ultrasound imaging will be available over the weekend. You wonder whether you can use a fecal occult blood test to rule out intussusception in this patient.

Search Strategy

Pubmed
((("occult blood"[MeSH Terms]) OR occult blood[Text Word]) OR occult bleeding[Text Word])) OR FOB[Text Word]) OR FOBT[Text Word])) AND (("intussusception"[MeSH Terms]) OR intussusception[Text Word])

Medline OVID interface
(intussusception.mp. or exp Intussusception/) AND (occult blood.mp. or exp Occult Blood/ or (FOBT or FOB).mp. or occult bleeding.mp)

Search Outcome

PubMed (Conception – Feb 20th, 2017
Medline OVID interface (1946 to February Week 2 2017)
36 articles found from PubMed and Medline – 12 unique and relevant from title or abstract analysis
5 reviews, 5 case studies, and 2 topic summaries
Review articles were analyzed.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Mandeville, et al. 2012 USA	Patient aged 0-17 presenting to ED with diagnosis of intussusception	Retrospective cohort study via chart review	Negative fecal occult blood test	26% (25/98 patients with intussusception)	- Not all patients had documented guiaic or visual stool inspection for blood.
Klein et al. 2004 USA	Children seen in the children’s hospital ED in Washington with a suspicion of intussusception and underwent contrast enema	Retrospective cohort study	Negative fecal occult blood test	39% (7/18 patients with intussusception)	- Small sample size - Large number of cases missing guiac stool information
Harrington et al. 1998 Canada	3 months to 5 years of age and believed by ED attending to warrant air contrast enema to rule out intussusception	Prospective descriptive cohort study	Negative fecal occult blood test	Negative predictive value: 76%	- Lack of funding resulted in only 88 out of 245 eligible children to be surveyed - The limited presentation of data makes it difficult to make more conclusions regarding the occult blood test
Yamamoto et al. 1997	107 inpatient children with intussusception	Retrospective chart review	Negative fecal occult blood test (if none in stool or no gross blood on rectal exam)	59% (16/27 patients with intussusception)	- Not all patients received a fecal occult blood test – patients with obvious blood were excluded (explicitly) thereby changing the proportion of patients who would have had a negative result if all were included
Losek J and Fiete R. 1991 USA	Patients at Children’s hospital of Wisconsin with barium enema studies for evaluation of intussusception	Retrospective chart review	Negative fecal occult blood test	25% (4/16 of patients with intussusception)	- Not all eligible patients had stool tested for blood - Small sample size

Comment(s)

All studies had fewer than 100 patients, and only one of the studies directly looked at the utility of a fecal occult blood test in a prospective design on all enrolled patients in the study. However, that prospective study was stopped prior to enrolling the prespecified number of patients due to lack of funding.

Clinical Bottom Line

A negative fecal occult blood test cannot reliably rule out the diagnosis of intussusception.

References

1. Mandeville K , Chien M , Willyerd FA , et al . Intussusception: clinical presentations and imaging characteristics. Pediatr Emerg Care 2012;28:842–4
2. Klein EJ , Kapoor D , Shugerman RP . The diagnosis of intussusception. Clin Pediatr 2004;43:343–7.
3. Harrington L , Connolly B , Hu X , et al . Ultrasonographic and clinical predictors of intussusception. J Pediatr 1998;132:836–9
4. Yamamoto LG , Morita SY , Boychuk RB , et al Stool appearance in intussusception: assessing the value of the term “currant jelly”. Am J Emerg Med 1997;15:293–8.
5. Losek JD , Fiete RL Intussusception and the diagnostic value of testing stool for occult blood. Am J Emerg Med 1991;9:1–3.