Abstract
BACKGROUND: The aetiology of constipation in Parkinson's disease remains poorly understood. Defaecatory dyssynergia, anal sphincter spasticity and slow transit constipation may, individually or collectively, play a role. AIMS: In this retrospective cohort analysis of patients with Parkinson's disease and chronic constipation, we determined the utility of high-resolution anorectal manometry, balloon expulsion and wireless motility capsule testing in defining the underlying aetiology for constipation. METHODS: In this retrospective cohort study, consecutive patients with Parkinson's disease and chronic constipation underwent clinical assessment, manometry with balloon expulsion and wireless motility capsule testing using standard protocols. RESULTS: We studied 66 patients fulfilling Rome IV criteria for functional constipation. Most patients (89%) had abnormal manometry, exhibiting various types of defaecatory dyssynergia (mostly types II and IV), abnormal balloon expulsion, diminished rectal sensation and, in some, lacking rectoanal inhibitory reflex. 62% exhibited colonic transit delay by wireless motility capsule study, while 57% had combined manometric and transit abnormalities, suggesting of overlap constipation. Symptoms of infrequent defaecation, straining and incomplete evacuation were not discriminatory. There was a relationship between constipation scores and colonic transit times (p=0.01); Parkinson's disease scores and duration were not correlated with either the manometric or transit findings. Faecal incontinence was seen in 26% of the patients. CONCLUSIONS: Chronic constipation in patients with Parkinson's disease may reflect pelvic floor dyssynergia, slow transit constipation or both, and may be associated with faecal incontinence, suggesting both motor and autonomic dysfunction. Anorectal manometry and wireless motility capsule testing are useful in the assessment of these patients.