High-resolution anorectal manometry profile in patients with chronic constipation versus control

Studies comparing chronic constipation (CC) and asymptomatic subjects are lacking in our population. This study aimed to compare the high-resolution anorectal manometry (HRAM) profiles of patients with CC and healthy volunteers (HV), as well as patients with functional defecation disorders (FDD) and those without in the constipation group.

This retrospective comparative study included patients with CC who underwent HRAM and a balloon expulsion test (BET). As historical controls, healthy volunteers were recruited. If both ARM and BET were abnormal, FDD was diagnosed using ROME-IV criteria.

Total 120 CC and 60 HV as controls were included. Maximum anal squeeze pressure (205 ± 62 vs. 170 ± 35 mmHg, p = 0.001), rectal sensations (1st sensation 49 vs. 40 ml, p = 0.024), desire to defecate (125 vs. 105 ml, p = 0.011) and maximum tolerable volume 171 vs. 150 ml, p = 0.018) were found to be significantly higher in CC patients as compared to controls. Median anal relaxation (15.5% [- 8.0 to 37.5] vs. 58.0% [34.0-77.0], p = 0.001), median defecation index (1.27 [0.88-1.74] vs. 2.00 [1.12-3.49], p = 0.001) and median recto-anal pressure gradient (17.50 [- 10.25 to 39.0] vs. 39.50 [7.50-69.0], p = 0.001) were significantly lower in CC patients. BET was not significant between CC and healthy volunteers (53% vs. 45%, p = 0.37). FDD was found in 57.5% of CC patients. Patients with FDD had higher anal residual pressure (95 ± 26 vs. 45 ± 21 mmHg, p = 0.001) and lower recto-anal pressure gradients than those without FDD (- 4.5 vs. 36 mmHg, p = 0.001). Rectal sensations were comparable in both FDD and non-FDD groups.

The clinical and manometric profiles of CC and HV patients differed significantly. FDD and rectal hyposensitivity were more common in those with CC. Type-1 recto-anal dyssynergia was the most common FDD sub-type.