practical diagnostic approach to chronic diarrhoea...approach to chronic diarrhoea mashiko setshedi...
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Practical Diagnostic Approach to Chronic Diarrhoea
Mashiko Setshedi 01 Feb 2019
Overview
Gastroenterology.1999;116(6):1464-1486.AmJEpidemiol1992;136:165–77.
Several hundred possible differential diagnoses
Chronic diarrhoea is common (3-5% of population)
Considerable diagnostic challenge
AmFamPhysician2011;84(10):1119-1126
What is chronic diarrhoea?
? Stool form, frequency, consistency Objective >200g of stool per day (unreliable) Accepted definition > 3 BMs per day Bristol ≥ 5 Chronic > 4 weeks
N.B: Exclude pseudo-diarrhoea (increased frequency, but normal consistency
Sub-types of diarrhoea
OLD
Osmotic Secretory
Inflammatory
Fatty
Dysmotility
NEW
Watery (osmotic, secretory, dysmotility)
Subtypes
Fatty
Inflammatory
AmFamPhysician2011;84(10):1119-1126
AmFamPhysician2011;84(10):1119-1126
AmFamPhysician2011;84(10):1119-1126
AmFamPhysician2011;84(10):1119-1126
PrimarySclerosingCholangi2s(PSC)DescribediarrhoeaOnset?PaCern
-conFnuous-intermiCent-nocturnalsymptoms
Associatedfeatures(pain,fever,gasetc)Alarmfeatures(new-onsetdiarrhoea,persistentbloodinstool,unintenFonalLOW)
Approach - history
PrimarySclerosingCholangi2s(PSC)DescribediarrhoeaOnset?PaCern
-conFnuous-intermiCent-nocturnalsymptoms
Associatedfeatures(pain,fever,gasetc)Alarmfeatures(new-onsetdiarrhoea,persistentbloodinstool,unintenFonalLOW)
Approach - history
PrimarySclerosingCholangi2s(PSC)DescribediarrhoeaOnset?PaCern
-conFnuous-intermiCent-nocturnalsymptoms
Associatedfeatures(pain,fever,gasetc)Alarmfeatures(new-onsetdiarrhoea,persistentbloodinstool,unintenFonalLOW)Associa2ons
-travel,food(dairy,sweeteners,FODMAPS,gluten,alcohol,caffeine,liquorice)
Approach - history
PastmedicalhistoryFamilyhx(IBD,coeliacdisease)OthermedicalcondiFons-thyroid,DM,collagenvasculardisease,pancreaFcdiseasePrevioussurgery(e.g.SBresecFon,cholecystectomy)PreviousradiotherapyMedica2ons(over700implicated)
AmFamPhysician2011;84(10):1119-1126
VitalsignsGeneralappearance–anorexia/bulimiaOedema,lymphnodesThyroidmassSkinrashes(DH),flushingAbdomen–scars,tenderness,masses,organomegalyRectalexam-sphinctertoneandsqueeze,fistulae
Approach – physical examination
Diagnostic objective
Make a positive diagnosis with minimal investigations
Detect common but underdiagnosed disorders such as bile acid diarrhoea, microscopic colitis, lactose malabsorption or post-radiation diarrhoea
Exclude cancer or inflammation
Initial approach
17
Hb,Feifanaemic,CRP,albumin,TSH,coeliacserologyANDStoolMCS,ova,cysts,parasites,faecalcalprotecFn(>50g/g),considerFIT
IfnegaFve,and<40,andnoalarmfeaturesandmeetsRomeIV
ConfirmIBS.Ifneedsbe,flexiblesigmoidoscopy
IftroublesomesymptomsdespitetreatmentforIBS
ConsiderCoeliacdisease(g-scope+duodenalbiopsies)MicroscopiccoliFs(colonoscopy+biopsies)Bilesaltdiarrhoea(empiricbileacidsequestrants)
Who should be investigated further?
Abnormal initial tests Normal first-line investigations with severe symptoms severe enough to impair QOL No response to initial treatment/ongoing symptoms Suspected organic disease
Watery Inflammatory Fatty Other
Osm>125mmol/kgOSMOTIC
HistoryosmoFclaxaFvesWorsewithdairyproducts–hydrogenbreathtestConsidercoeliacdisease
ApplyRomeIVIBSorfuncFonaldiarrhoeaExcludecoeliacdisease
Osm<50mmol/kgSECRETORY
NormalOsmDYSMOTILITY
StoolanalysisColonoscopy(microscopiccoliFs≥8biopsies)MRI/CTTSH/ACTHTestsforhormone-secreFngtumoursLaxaFvescreen
Watery
Osm>400mmol/kgCONTAMINATION/SPURIOUS
StoolanalysisposiFveforRBCs,WBCs
Colonoscopy+biopsies±FCP
ConfirmIBDorinfecFouse.g.pseudomembranous,amoebic,CMVcoliFs
Treatappropriately Inves2gateothercauses
Inflammatory
YES NO
Hb,Alb,Fe,VitB12,folate
Malabsorp2on
Gastroscopy+duodenalbiopsiesMREVCEDBESBBO–trialanFbioFcs
Maldiges2on
FaecalelastaseMRIpancreas(CTifMRIunavailable)
Fatty
If all else fails, think constipation!
N.B:withoverflowdiarrhoeaExcludefaecalinconFnence
-KUB-analmanometry-endoanalUS
7-step approach
3.Isitcolonic,smallbowelorpancreaFcdisease?
1.Isitdiarrhoea?Establishthatitis.
2.IsitfuncFonalororganic?
4.Isitinflammatory,watery,faCy?5.Determinespecificcause.
6.CoulditbeconsFpaFon/pelvicpathology?
7.CoulditbefacFFous(4-20%)?
Learning Points
Testearlyforcoeliacdisease
Minimal/non-invasivestep-wiseinvesFgaFonstoarriveatadiagnosis
MostchronicdiarrhoeaisduetocolonicabnormaliFesandgenerallynotinfecFous
SomecondiFonsaremorecommonthanwethink
Itbeginswithafocused,comprehensivehistory