Orocaecal transit timeinhealth andinthyroid disease

SUMMARY Altered bowelhabit commonly occursinthyroid disease. Wemeasured orocaecal transit inhealthy volunteers andinhyperthyroid andhypothyroid patients before andafter treatment, using thelactulose hydrogen breath testincorporating a standard liquid mealtoobtain a more physiological assessment. Meantransit timein12control subjects was 85(8)minutes (mean(SE)) (meancoefficient ofvariation between replicate studies, 8-6%(3%)). Ineighteen hyperthyroid patients transit was more rapid at49(4)minutes (p<0-01). Tenhypothyroid patients hadatransit timesimilar tocontrols at91(9)minutes. Transit timereturned tonormal inthyrotoxic patients after treatment butineight hypothyroid patients retested, itremained unchanged. Ourfindings suggest that (a)theinclusion ofaliquid mealprovides areproducible methodofmeasuring orocaecal transit using thelactulose hydrogen breath test, (b)rapid small boweltransit inthyrotoxicosis may beone factor inthediarrhoea whichisafeature ofthedisease and(c)ifaltered guttransit isthecauseof sluggish bowelhabit inhypothyroidism, delay inthecolon, andnotsmallbowel, islikely tobe responsible.