Background: Some consider that patients with visceral hypersensitivity may represent a separate entity within the IBS population not only from a pathophysiological but also from a clinical perspective. The aim of this prospective exploratory study was to assess whether characteristics of abdominal pain in IBS patients could be suggestive of hypersensitivity.
Methods: This prospective study included consecutive IBS patients selected by Rome III criteria. Validated scores (IBS-SSS, Bristol stool scale, HADS) were used to phenotype patients who were also asked to describe the main location of their abdominal pain on a simple image (abdomen divided into 6 zones). Progressive isobaric rectal distensions were performed to demonstrate, with the ascending method of limits, allodynia (pain threshold lower than 24 mmHg).
Key results: Fifty patients (women: 72%), 42.6 ± 15.7 years old, were included. Sub-types were IBS-D, IBS-C and IBS-M in 58%, 22% and 20% of cases, respectively. Allodynia was present in 18% of cases. Neither IBS-SSS nor intensity of pain was predictive of hypersensitivity. In hypersensitive patients, pain was more often located in one of the two iliac fossa (P = 0.02) and located outside these areas in only 11% of cases. The sensitivity and the specificity of this pain location to differentiate hyper from normosensitive patients were 0.89 and 0.59, respectively.
Conclusions & inferences: The location of pain is different between hyper and normosensitive IBS patients. Pain located outside one of the two iliac fossa suggests that the patient is normosensitive.
Keywords: abdominal pain; clinical practice; irritable bowel syndrome; pathophysiology; visceral hypersensitivity.
© 2018 John Wiley & Sons Ltd.