Bowel symptoms and management practices in Parkinson’s disease and related conditions: results from the PRIME-UK study

Objective:
To describe bowel symptoms and constipation management practices in a large, representative cross-sectional study of Parkinson’s and related disorders.

Background:
Bowel symptoms, particularly constipation, are common in patients with parkinsonism [1] and can have significant psychological and social implications, as well as affecting medication absorption [2]. There remains a limited evidence base for what common treatments for constipation are effective in Parkinson’s disease [3]. Given clinical decision making is left to experience, current prescribing practices are unknown.

Method:
Data was collected from the PRIME-UK single-centred cross-sectional study using self-reported participant questionnaire booklets. Bowel symptoms were collected using two scales: The Scale for Outcomes in Parkinson’s disease – Autonomic dysfunction (SCOPA – AUT) and the neurogenic bowel dysfunction score (NBD). Current laxative use was determined from participants’ self-reports.

Results:
The study included 445 participants (median age 75.5 (IQR 48.9-91.4), 34.4% female). Median duration of disease was 6.2 years (IQR 0-28). 249 (56.6%, 95% CI 51.8-61.3%) participants experienced <2 bowel movements per week. 187 participants took laxatives. The majority were taking 1 laxative (n=80, 76.9%) followed by 2 laxatives (n=16, 15.4%). The most commonly prescribed laxative group was osmotic (n=82, 78.9%) followed by stimulant (n=29, 27.9%) and softeners (n=14, 13.5%). There was very low use of therapies outside these categories.

Conclusion:
Bowel symptoms and therefore laxative prescribing were common in this representative cohort of people with Parkinsonism. There appears to be a trend towards prescribing osmotic laxatives although the evidence base and rationale is limited. Given the majority of participants continue to be constipated, despite being on a single agent, patients may be undertreated or have an inadequate response to current treatments. Research is needed to determine an evidence-based treatment algorithm for constipation management in PD including escalated treatment regimes, which may provide better symptom control.