Regional Gastrointestinal Transit and Contractility Patterns Vary in Postural Orthostatic Tachycardia Syndrome (POTS)

Background Postural orthostatic tachycardia syndrome (POTS) is an autonomic disorder that affects multiple organs, including the gastrointestinal system. These patients often have multiple GI complaints with a severe impact on their quality of life. GI dysmotility patterns in POTS remains poorly understood and difficult to manage. Aims The aim of this study was to investigate the diagnostic yield of wireless motility capsule in patients with gastrointestinal symptoms and POTS, with use of a symptomatic control group without POTS as a reference. Methods We retrospectively reviewed the charts of patients who had both autonomic testing and wireless motility capsule between 2016 and 2020. The two groups were divided into those with POTS and those without POTS (controls) as diagnosed through autonomic testing. We compared the regional transit times and motility patterns between the two groups using the data collected from wireless motility capsule. Results A total of 25% of POTS patients had delayed small bowel transit compared to 0% of non-POTS patients ( p = 0.047). POTS patients exhibited hypo-contractility patterns within the small bowel, including decreased contractions/min (2.95 vs. 4.22, p = 0.011) and decreased motility index (101.36 vs. 182.11, p = 0.021). In multivariable linear regression analysis, migraine predicted faster small bowel transit ( p = 0.007) and presence of POTS predicted slower small bowel transit ( p = 0.044). Conclusions Motility abnormalities among POTS patients seem to affect mostly the small bowel and exhibit a general hypo-contractility pattern. Wireless motility capsule can be a helpful tool in patients with POTS and GI symptoms as it can potentially help guide treatment.