STOOL EXAMINATION

STOOL EXAMINATION

STOOL EXAMINATIONDR RONALDA DE LACYWHY IS IT DONE?ColourConsistencyFrequencyBloodBacteriaVirusesParasitesFungalPancreatic functionIntestinal malabsorptionInflammatory markers

STOOL COLOUR

3

STOOL CONSISTENCY

STOOL FREQUENCYBreastfed infants stool after every breastfeed- once to twice a week

Children on average 1 to 2 stools per day Some children might have a stool every 2nd day

BLOOD FRESH BLOODLower GIT bleed- anal fissure- rectal haemorrhoids- polyps- inflammatory bowel disease- infections i.e. Shigella, salmonella- meckels diverticulum- intussception- NEC

BLOODALTERED BLOOD (MALAENA)Upper GIT bleed- oesophagitis- mallory-weiss tear- gastritis- ulcersgastric, duodenal, small bowel- vascular malformations- anastomotic sitesBACTERIASHIGELLAGram-negative rodNonspore forming, non-motileFour serogroups- S. Dysenteriae (12 serotypes)- S. Flexeneri (6 serotypes)- S. Boydii (18 serotypes)- S. Sonnei (1 serotype)S. Flexeneri most frequently isolated in developing world 60% of casesS. Sonnei most frequently isolated in developed world 77% of cases

SHIGELLA

BACTERIASALMONELLAGram-negative rodNonspore forming, motileMany serotypesSALMONELLA

BACTERIACHOLERAOnly infects humansTransmission by faecal contamination of water and foodOrganism secretes an enterotoxinResults in watery diarrhoea CHOLERA

BACTERIACAMPYLOBACTERGram-negative rod- comma or S-shapedTransmission is faecal-oralCattle, chickens and dogs are sourcesCAMPYLOBACTER LIFECYCLE

BACTERIAYERSINIA ENTEROLITICAGram-negative oval rodContaminated foodEnterocolitisBACTERIACLOSTRIDIUM DIFFICILEAntibiotic useFresh stool sampleBACTERIAMYCOBACTERIATuberculosisTransmission by respiratory dropletsMainly respiratory diseaseDissemination can result in intestinal involvement

BovisTransmission by unpasteurised cows milkIntestinal involvementDifficult to culture from stool-need tissue

VIRUSROTAVIRUSRNA virusMost common cause for diarrhoeaVaccine availableDiagnosis antigen testing on the stoolROTAVIRUS

VIRUSADENOVIRUSDNA virus31 antigenic typesHigh swinging feversPneumoniaConjunctivitisDiarrhoeaDiagnosis antigen testing on the stoolADENOVIRUS

PARASITESENTEROBIUS VERMICULARISPinworm infectionLifecycle confined to humansEggs recovered from peri-anal area with tapeAdult worms may be found in the stoolENTEROBIUS VERMICULARIS

ENTEROBIUS VERMICULARIS(PINWORM)

PARASITESASCARIS LUMBRICOIDESTransmission-eating eggs in contaminated soilDiagnosis- oval eggs in the stool or adult worms seenASCARIS LUMBRICOIDES EGG

ASCARIS LUMBRICOIDES LIFECYCLE

PARASITESTRICHURIS TRICHURIUMWhipworm infectionTransmission-eating eggs in contaminated soilDiagnosis- barrel-shaped eggs in the stoolTRICHURIS TRICHIURA EGGS

TRICHURIS TRICHURIUM LIFECYCLE

PARASITESTAENIA SOLIUMIngestion of larvae in undercooked porkDiagnosis- proglottids in stoolgravid proglottids have 5-10 primary uterinebranches

TAENIA SAGINATAIngestion of larvae in undercooked beefDiagnosis- gravid proglottids have 15-20 primary uterine branches

TAENIA EGG

TAENIA SAGINATAFOUR SUCKERSNO HOOKS

TAENIA SOLIUMFOUR SUCKERSDOUBLE ROW OF HOOKS

TAENIA LIFECYCLE

PARASITES-PROTOZOAGIARDIA LAMBLIAFlagellated protozoanWaterborne transmissionFaecal-oral routeInfects the small intestineDifficult to isolate, need minimum of 3 stool specimensDiagnosis- trophozoites or cysts in diarrhoeal stools- trophozoites- pear-shaped, 2 nuclei, 4 pairs of flagella, suction disk GIARDIA LAMBLIATROPHOZOITE

PARASITES-PROTOZOACRYPTOSPORIDIUMCoccidian protozoaWaterborne transmissionDirect person to person contactImmunocompromised patientsDiagnosis- oocysts in faecal smears

CRYPTOSPORIDIUM OOCYSTSCRYPTOSPORIDIUM OOCYSTS-EM

PARASITES-PROTOZOAENTAMOEBA HISTOLYTICATransmission-faecal-oral route, contaminated food and waterDiagnosis- trophozoites in diarrhoeal stools- cysts in formed stools 4 nuclei

ENTAMOEBA HISTOLYTICACYST

PARASITES-PROTOZOAISOSPORA BELLIFaecal-oral transmissionImmunocompromised patientsDiagnosis-oocysts in faecal specimen

ISOSPORA BELLI OOCYSTS

FUNGALCANDIDA ALBICANSPart of normal gut floraOvergrowth in diabetes, immunocompromised patients and prolonged antibiotic use.Diagnosis- oval yeast with a single bud in the stool

CANDIDA ALBICANS

PANCREATIC FUNCTIONFaecal elastase>200ug/g faeces - normalLow in chronic diarrhoea100 mosm/l osmotic diarrhoeaFOG