Idiopathic bile acid malabsorption: long-term outcome

Area of Science:

• Gastroenterology
• Clinical Medicine
• Diagnostic Imaging

Background:

• Idiopathic bile acid malabsorption (IBAM) is a rare condition presenting as chronic diarrhoea.
• The natural history and long-term outcomes of IBAM have not been well-documented.
• Exclusion of malignancy and inflammatory bowel disease is crucial before diagnosing IBAM.

Purpose of the Study:

• To determine the long-term outcome of severe idiopathic bile acid malabsorption.
• To assess symptom resolution and treatment requirements over time.
• To evaluate objective markers of bile acid malabsorption using 75Se-homocholic acid taurine (75SeHCAT) retention.

Main Methods:

• A cohort of 23 patients diagnosed with IBAM in 1989 was studied.
• Long-term follow-up involved subjective assessment via questionnaires and objective assessment using 75SeHCAT scans.
• Patients had previously responded to bile acid chelator therapy (cholestyramine or aluminium hydroxide).

Main Results:

• After a mean follow-up of 99.2 months, 14 patients remained in the study.
• Seven patients (50%) experienced spontaneous remission and discontinued treatment.
• Of the seven symptomatic patients, diarrhoea was controlled with cholestyramine or anti-diarrhoeal agents; 75SeHCAT scans indicated persistent malabsorption.
• Three asymptomatic patients showed improved 75SeHCAT retention, suggesting resolution.

Conclusions:

• Idiopathic bile acid malabsorption is a rare cause of diarrhoea, necessitating thorough investigation to rule out other serious gastrointestinal conditions.
• Long-term follow-up is recommended as some patients may develop other gastrointestinal diseases.
• Approximately 50% of patients with IBAM may achieve spontaneous remission, potentially eliminating the need for ongoing medication.