Objective: To analyze the different influence of body position on wireless high-resolution anorectal manometry parameters and in classification for chronic constipation patients.
Patients and methods: Fifty consecutive patients with chronic constipation and 20 healthy volunteers were included in this study, all of whom accepted the Rome IV constipation questionnaires, underwent rectal balloon expulsion test and wireless high-resolution anorectal manometry. The wireless high-resolution anorectal manometry was performed in the left lateral, seated, and squatting positions for every study subject. The Statistical Product and Service Solutions (SPSS) 21.0 software (IBM Corp., Armonk, NY, USA) was used for statistical analysis.
Results: The anal sphincter resting pressure, anal sphincter squeezing pressure, and rectal internal pressure during the evacuation in the seated position and squatting position were significantly higher than those in the left lateral position in both the volunteer group and patient group, without a significant difference between the seated position and squatting position. The initial perception threshold was higher in the patient group than in the volunteer group. The wireless high-resolution anorectal manometry in different positions combined with the rectal balloon expulsion test mainly affects the diagnosis of the subtype of inadequate defecatory propulsion.
Conclusions: Compared with the left lateral position test, the wireless high-resolution anorectal manometry in the seated position and squatting positions is more consistent with the human physiological bowel condition, and the result of the test can be affected by the body position. The wireless high-resolution anorectal manometry can differentiate between subtypes during the diagnosis of inadequate defecatory propulsion.