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Toronto Notes 2019 Small and Large Bowel
Prognosis
• chronicrelapsingpatterninmostpatients
• 10-15%chroniccontinuouspattern
• >1attackinalmostallpatients
• morecolonicinvolvementinthe1styrcorrelateswithincreasedseverityofattacksandincreased
colectomy rate
■ colectomy rate = 1% for all patients after the 1st yr; 20-25% eventually undergo colectomy
• normallifeexpectancy
• ifproctitisonly,usuallybenigncourse,lifetimeriskofextensionis15%
• stoolcalprotectinincreasinglyrecognizedasamarkerofbowelmucosalinflammation,reported
especially to be useful in monitoring the activity of inflammatory bowel disease, but accuracy is still controversial
Irritable Bowel Syndrome
Definition
• aformoffunctionalboweldisease;morethanjustalabelforGIsymptomsunexplainedafternormal investigations
Epidemiology
• 20%ofNorthAmericans
• onsetofsymptomsusuallyinyoungadulthood • F>M
Pathophysiology
• associatedwitheitherabnormalperceptionofintestinalactivityorabnormalintestinalmotility • abnormalmotility:multipleabnormalitiesdescribed;unclearifassociationsorifcausative
• psychological:stressmayincreaseIBSsymptomsbutprobablydoesnotcauseIBS
• 4maintypesofIBS
■ IBS-D: IBS with predominant diarrhea
■ IBS-C: IBS with predominant constipation
■ IBS-M:IBS-mixedwithbothdiarrheaandconstipation(each>25%ofallabnormalbowelmovements) ■ IBS untyped: insufficient abnormality in stool consistency to meet other types
Diagnosis
Table 13. Rome IV Criteria for Diagnosing Irritable Bowel Syndrome
IBS Rome IV Criteria
Recurrent abdominal pain, on average, at least 1 day per week in the last 3 months, associated with 2 or more of the following: 1. Related to defecation
2. Associated with a change in frequency of stool
3. Associated with a change in form (appearance) of stool
Symptom onset at least 6 months before diagnosis and criteria present during the last 3 months
The following are supportive, but not essential to the diagnosis:
Abnormal stool frequency (>3/d or <3/wk)
Abnormal stool form (lumpy/hard/loose/watery) >1/4 of defecations
Abnormal stool passage (straining, urgency, feeling of incomplete evacuation) >1/4 of defecations Passage of mucus >1/4 of defecations
Bloating
Diagnosis of IBS Less Likely in Presence of “Red Flag” Features
Gastroenterology G23
Weight loss
Fever
Nocturnal defecation
Normal Physical Exam
Investigations
Anemia
Blood or pus in stool
Abnormal gross findings on flexible sigmoidoscopy
• ifhistoryconsistentwithRomeIVcriteria,noalarmsymptoms,andnofamilyhistoryofIBDor colorectal cancer, limited investigations required
• aimistoruleoutdiseaseswhichmimicIBS,particularlyceliacdiseaseandIBD
• investigationscanbelimitedtoCBC,inflammatorymarkers(ESR,CRP)andceliacserology
• if available, fecal calprotectin is likely more reliable test to rule out IBD
• consider TSH, stool cultures depending on clinical circumstances
• considercolonoscopy(e.g.ifalarmingfeaturespresent,familyhistoryofIBDorage>50)
Treatment
• education:reassurance,explanation,support,aimforrealisticgoals
• relaxationtherapy,biofeedback,hypnosis,stressreduction,probablyexercise
• dietary:lowFODMAP(FermentableOligo-,Di-,MonosaccharidesAndPolyols)dietforpain,bloating
IBS Mimickers
• Enteric infections e.g. Giardia
• Lactose intolerance/other disaccharidase
deficiency
• Crohn’s disease
• Celiac sprue
• Drug-induced diarrhea
• Diet-induced (excess tea, coffee, colas)
gas, irregular bowel movements