Be Kind to Your Behind: A Systematic Review of the Habitual Use of Bidets in Benign Perianal Disease

Table 4

Effect of bidet use on resting anal pressure.

Study	Study type	N	Methodology	Comparator group	Intervention group	Outcome extracted	Anal pressure (mmHg)
							Comparator	Intervention	Difference
Ryoo et al. [28]	Prospective cohort	20	20 healthy volunteers had anal pressures measured at the anal high-pressure zone (HPZ) before and after 1 minute of bidet use with different settings	Before bidet use	Bidets set at different pressures (40 mN and 80 mN), different temperatures (24°C and 38°C), and different jet types (wide or narrow)	Pressure at HPZ at 38°C, 40 mN, and wide jet	96.1 ± 22.5	81.9 ± 23.3	14.2 ()
Ryoo et al. [29]	Prospective cohort	40	40 healthy volunteers had anal pressures measured at the HPZ before and after 3 minutes of bidet use	Change in the anal HPZ after 3 minutes of sitz bath use	Change in the anal HPZ after 3 minutes of bidet use	Change in pressure at HPZ after sitz bath and bidet use	88.1 − 69.6 = 18.5 ()	90.2 − 71.3 = 18.9 ()	0.04 ()