The pathogenesis of post-irradiation chronic diarrhoea: Measurement of SeHCAT and B₁₂ absorption for differential diagnosis determines treatment

The absorption of vitamin B₁₂ and of a synthetic bile acid analogue ⁷⁵SeHCAT was measured simultaneously in 26 patients presenting with persistent diarrhoea following pelvic irradiation for treatment of carcinoma of the cervix. Four groups were identified, namely patients with isolated bile acid malabsorption, patients with isolated B₁₂ malabsorption, patients with malabsorption of both and those with malabsorption of neither compound. The therapeutic implications are different for each. Measurement of B₁₂ and bile acid absorption comprises an important new test for the management of patients with this disabling and unpleasant complication of radiotherapy.