Irritable Bowel Syndrome vs Inflammatory Bowel Disease

Transcription

1 Irritable Bowel Syndrome vs Inflammatory Bowel Disease Lana Bistritz MD FRCPC Royal Alexandra Hospital Faculty/Presenter Disclosure Faculty: Lana Bistritz Relationships with financial sponsors: Grants/Research Support: Pendopharm Speakers Bureau/Honoraria: Takeda Consulting Fees: Other: 1

2 Objectives Patients with abdominal pain and altered bowel habits Overlap in presentation between IBS and IBD Common (15% prevalence) Goal to avoid exhaustive, expensive testing Increase patient and physician confidence in the diagnosis of IBS At the end of this session, participants will be able to Select appropriate laboratory investigations to distinguish IBS vs IBD C-reactive protein Fecal calprotectin Clinical History Rome III criteria Recurrent abdominal pain > 3 months PLUS 2 of: Improves with defecation Change in frequency of stool Change in form of stool Sensitivity 70%, Specificity 82% for diagnosis of IBS Increased specificity for IBS when combined with normal Hb, normal CRP, high somatization score 1/3 inflammatory bowel disease patients meet Rome III criteria Chronicity may be the most helpful symptom Alarm symptoms Low positive predictive value Halpin et al Am J Gastro 2012;107: Sood et al Am J Gastro 2016;111:

3 Should these patients have a colonoscopy? Prospective, case control study non-constipated IBS vs controls (CRC screening) n=900 Most findings were incidental, not responsible for symptoms Hemorrhoids 18%, diverticulosis 9%, polyps 15% Lower prevalence of adenomas, diverticulosis than control group 1.9% patients identified an alternate diagnosis Microscopic colitis 7 patients (all >45 years old) UC 1 patient Crohn s 1 patient ACG recommendations: routine colon imaging not recommended in patients younger than 50 with typical IBS symptoms and no alarm features Chey et al Am J Gastro 2010;105: Serum markers of inflammation: ESR, C- reactive protein Produced by hepatocytes in response to IL-1, IL-6 Non-specific C-reactive protein Meta-analysis: CRP levels predictive of IBD >17 mg/l 52% predictive probability of IBD >27 mg/l >90% predictive probability of IBD Not all IBD patients mount a C-reactive protein response ESR Meta-analysis: did not discriminate IBD vs IBS vs healthy control Menees et al Am J Gastro 2015:110:

4 CRP <5 mg/l, <1% likelihood IBD ESR not predictive of IBD Fecal Calprotectin Neutrophilic granular protein released from mucosal into stool Sensitivity 93% specificity 94% at cutoff of 50ug/g Systematic review, mainly referral population Can order via Dynalife They freeze sample, send to U of A Sent to Ontario $60 plus shipping costs Approx 14 days turnaround time Reference range <50 ug/g Availability varies by region Lethbridge- only ordered by GI Waugh et al Health Technol Assess 2013;17:55 4

5 Fecal calprotectin meta-analysis Fecal calprotectin <40 ug/g, less than 1% chance of IBD Wide range of fecal calprotectin for patients with IBS Most patients with elevated fecal calprotectin <200 ug/g will NOT have IBD High Negative predictive value, poor Positive predictive value Menees et al Am J Gastro 2015:110: What about fecal calprotectin in primary care? Lower prevalence of IBD, higher false positives Retrospective review, 50 ug/g cutoff Sensitivity 73%, specificity 65%, PPV 5.4%, NPV 98.9% 19% of patients with negative fecal calprotectin still referred for colonoscopy Older, maybe concern was cancer? Good to rule out IBD Causes of elevated fecal calprotectin GI infection GI inflammation (IBD, celiac, microscopic colitis, SIBO, possibly IBS) NSAIDS, PPI How much to investigate patients with elevated fecal calprotectin? Conroy et al J Clin Path 71:4 5

6 UK Care Primary Care Pathway Turvill Frontline Gastro 2018;9: Adults Cancer not suspected Normal initial workup (Hb, TTG, CRP, TSH) 100 ug/g cutoff 1005 patients Sensitivity 0.94 specificity 0.92 PPV 0.51, NPV 0.99 Cost savings 60,00-100,000/ 1000 patients 85% pts 30% patients had fecal calprotectin ug/g 8% referred to GI None Dx with IBD 53% pts What about FIT test? No evidence for use in distinguishing IBS vs IBD Some data supporting use to confirm a flare in patients with established diagnosis of IBD Validated as a screening tool for CRC Labs will be rejecting samples on patients < age 40 6

7 Other resources GI Clinical Pathways Calgary Zone ( GERD, dyspepsia, H pylori, IBS, chronic constipation, chronic diarrhea Provincial implementation (Digestive Health Strategic Clinical Network) upcoming ereferral Advice Via Netcare login Pilot Asynchronous link with GI/Hepatology specialist for non-urgent indications Not a route for GI referrals Conclusions Clinical history important (alarm features, chronicity, somatization) No role for ESR Baseline labs including C-reactive protein first If labs normal and diagnostic uncertainty persists, then fecal calprotectin Fecal calprotectin <50 Manage as IBS, no GI referral needed Fecal calprotectin Refer if >50 years old Trial of IBS therapy prior to referral if < 50 yrs Fecal calprotectin > 100 Refer to GI if > repeat test vs refer to GI 7