Background: Constipation in adults associated with a grossly dilated rectum and recurrent faecal impaction, idiopathic megarectum, is rare. The aetiology of idiopathic megarectum is unknown, but may involve neuromuscular or behavioural factors. It is unknown whether the condition is reversible. This study aimed to determine the efficacy of behavioural therapy, including biofeedback, in such patients.
Methods: Six patients (4 female; median age 27) with a history of rectal faecal impaction and a grossly dilated rectum on radiological examination were evaluated by structured questionnaire before, immediately after biofeedback therapy, and on follow-up. Physiological testing was performed before treatment, and 2 patients were evaluated by repeat physiological testing and contrast radiology on follow-up.
Results: On median follow-up of 18 months (range 11-27), five patients felt major and one patient minor improvement in symptoms, including two with complete symptom relief. Four patients came off laxatives without recurrent faecal impaction. In the 2 studied patients rectal size did not appear to decrease.
Conclusion: Behavioural retraining, including biofeedback, improved symptoms in most patients with idiopathic megarectum. In some patients symptoms completely resolved, without the need for laxatives. Although further studies are necessary in terms of both larger number of patients and longer follow-up period, behavioural treatment may be useful for such patients.