Diagnosing Functional Disorders of the Lower Gastrointestinal Tract Clinically: Are We Moving Nearer Or Farther?

Abstract

Introduction: In clinical practice, the diagnosis of functional bowel disorders and functional abdominal pain syndrome is predominantly one of exclusion. This study aimed at assessing the value of clinical symptoms, basicinvestigations and the utility of colonoscopy in differentiating organic disease from functional disorders of the lower gastrointestinal tract. Methods: Data was collected prospectively from consecutive patients with a lower gastrointestinal complaint requiringa colonoscopy for evaluation. The ability of the symptoms, clinical examination, abnormalities on basic laboratory parameters and colonoscopy to predict an underlying organic disease was assessed. Results: Eighty-three patients entered the study following the inclusion and exclusion criteria. 65.1% patients had afunctional disorder and 34.9% had an organic lower GI illness. No differences in the mean age or genderratio were noted between the two groups. The mean duration of symptoms in the functional group was significantly longer. The variables that showed statistical significance in differentiating an organic from a functional lower GI disease on multivariate analysis were passage of blood in stools (p = 0.02), weight loss (p = 0.01), abdominal tenderness (p = 0.004), anemia (p = 0.007), presence of mass abdomen (p = 0.01) and abnormalities on colonoscopy (p = 0.02). With the addition of colonoscopy to the diagnostic algorithm the sensitivity improved to 100% and specificity to 97%. Conclusion: Clinical diagnosis of functional bowel disorders have poor sensitivity and specificity, suggesting that it may be appropriate that the Rome criteria be expanded to include key alarm features, basic investigations and colonoscopy. Tabled 1Sensitivity, Specificity, PPV, NPV and efficacy at various stages of evaluation Vs final diagnosis Clinical Vs final diagnosis (stage I) Clinical + Investigations Vs final diagnosis (stage II) Clinical + investigations + colonoscopy Vs final diagnosis (stage III) STAGES Estimated value (%) 95% CI (%) Estimated value (%) 95% CI (%) Estimated value (%) 95% CI (%) Sensitivity 57 43-71 69 55-80 100 93-100 Specificity 83 64-94 62 42-79 97 82-100 PPV 86 71-95 77 63-88 98 90-100 NPV 51 36-66 51 34-68 100 87-100 Efficacy 66 55-76 66 55-76 99 93-100 Kappa Stats 0.35, p = 0.001 Fair agreement 0.29, p = 0.001 Fair agreement 0.97, p = 0.001 Perfect agreement Open table in a new tab