Clinical features and outcomes of adult idiopathic megarectum.

Abstract

Idiopathic megarectum is characterized by abnormal, pronounced rectal dilatation in the absence of identifiable organic pathology. Idiopathic megarectum is uncommon and under-recognized. This study aims to describe the clinical features and management of idiopathic megarectum. A retrospective review was undertaken on patients diagnosed with idiopathic megarectum with or without idiopathic megacolon over a 14-year period until 2021. Patients were identified from the hospital's International Classification of Diseases codes, and pre-existing clinic patient databases. Patient demographics, disease characteristics, healthcare utilization and treatment history data were collected. Eight patients with idiopathic megarectum were identified; half of the patients were female, with the median age of symptom onset being 14 years (interquartile range [IQR] 9-24). The median rectal diameter measured was 11.5 cm (IQR 9.4-12.1). The most common presenting symptom was constipation, bloating and faecal incontinence. All patients required prior sustained periods of regular phosphate enemas and 88% were using ongoing oral aperients. Concomitant anxiety and or depression were found in 63% of patients and 25% were diagnosed with an intellectual disability. Healthcare utilization was high with a median of three emergency department presentations or ward admissions related to idiopathic megarectum per patient over the follow-up period; 38% of patients required surgical intervention during the period of follow-up. Idiopathic megarectum is uncommon and associated with significant physical and psychiatric morbidity and high healthcare utilization.