Clinical and anorectal manometry profile of patients with functional constipation and constipation-predominant irritable bowel syndrome

Functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C) have significant healthcare impact. Clinical and investigative data of patients with these disorders in Indian population is scarce. We aimed to compare the clinical and anorectal manometric profile of patients with FC and IBS-C.

Consecutive patients with chronic constipation undergoing anorectal manometry (ARM) and balloon expulsion test (BET) were enrolled. Thirty healthy volunteers served as controls (HC). Functional defecatory disorder (FDD) was diagnosed according to ROME IV criteria if both ARM and BET were abnormal.

Of the 231 patients enrolled (median age 47 years, 87.8% males), FC and IBS-C were diagnosed in 132 (57.1%) and 99 (42.9%) patients, respectively. Significant clinical differences between FC and IBS-C patients included older age, lower stool frequency/week, higher frequency of straining, and greater frequency  of incomplete evacuation (p < 0.001). ARM revealed abnormal defecatory pattern in 55.3% (n = 73) FC patients and 47.5% (n = 47) IBS-C patients. Of them, 54.7% (40/73) of FC patients had inadequate defecatory propulsion while 89.4% (42/47) of the IBS-C patients had dyssynergic defecation (p < 0.001). Abnormal BET was seen in 67.4% of FC patients and 43.4% of IBS-C patients. Thus, FDD was diagnosed in 55.3% and 46.5% of FC and IBS-C patients, respectively. Rectal hyposensitivity was present in 60.6% of FC patients compared with 2% of IBS-C patients (p < 0.001).

There were significant differences in clinical and manometric profile of FC and IBS-C patients. Compared with IBS-C patients, FC patients were older, had higher prevalence of FDD, less often had dyssynergic defecation, and had higher prevalence of rectal hyposensitivity.