BowALS: understanding changing bowel habits in people with amyotrophic lateral sclerosis

Background: Amyotrophic lateral sclerosis (ALS), also known as motor neurone disease (MND), causes progressive weakness and ultimately death as a result of loss of motor nerves. Changes in bowel habit are common in people with ALS. This has been attributed to immobility, dehydration and dietary changes. Objective: To provide understanding of the prevalence of altered bowel habit in people with ALS, how this differs by stage of disease and how it impacts daily life. Methods: In a prospective cohort study (BowALS) in two UK ALS centres, 58 participants recorded their current and usual bowel habit using an online questionnaire which included the revised ALS functional rating scale (ALSFRS-R), Bristol stool chart, the EuroQol 5 questionnaire (EQ-5D) questionnaire and measured forced vital capacity. The same questionnaire was completed three times 6 months apart. Results: A total of 33 patients (57%) reported change in bowel habit in response to the first questionnaire and 43 patients (74%) reported change in bowel habit at some point during follow up. Change in bowel habit was more common at the first visit in patients with more advanced disease, as measured by lower ALSFRS-R (ALSFRS-R<34, 14/18 patients; ALSFRS-R >40, 6/18 patients; odds ratio 6.58, P=0.018). Change in bowel habit was also associated with lower self-reported health score on EQ-5D (median 60 vs 75, P=0.035). There was no correlation between ALSFRS-R and Bristol stool chart score, and no association between self-reported depression and change in bowel habit. Recommendations: Healthcare professionals should think proactively about preventing constipation in people with ALS, being aware that the prevalence of altered bowel habit increases with the level of disability.