Colorectal motility patterns and psychiatric traits in functional constipation and constipation-predominant irritable...

Functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C) represent a spectrum of constipation disorders. However, the majority of previous clinical investigations have focused on Western populations, with limited data originating from China.

To determine and compare the colorectal motility and psychiatric features of FC and IBS-C in an Eastern Chinese population.

Consecutive chronic constipation patients referred to our motility clinic from December 2019 to February 2023 were enrolled. FC and IBS-C diagnoses were established using ROME IV criteria, and patients underwent high-resolution anorectal manometry (ARM) and a colonic transmit test using the Sitz marker study. Constipation-related symptoms were obtained through questionnaires. Anxiety and depression were assessed by the Hamilton anxiety rating scale and the Hamilton Depression Rating Scale-21. The clinical characteristics and colorectal motility patterns of FC and IBS-C patients were compared.

No significant differences in sex, age or abdominal discomfort symptoms were observed between IBS-C and FC patients (all P > 0.05). The proportion of IBS-C patients with delayed colonic transit was higher than that of patients with FC (36.63% vs 15.91%, P < 0.05), while rectosigmoid accumulation of radiopaque markers was more common in the FC group than in the IBS-C group (50% vs 26.73%, P < 0.05). Diverse proportions of these dyssynergic patterns were noted within both the FC and IBS-C groups by ARM. IBS-C patients were found to have a higher prevalence of depression than FC patients (66.30% vs 42.42%, P < 0.05). The scores for feelings of guilt, suicide, psychomotor agitation, diurnal variation, obsessive/compulsive disorder, hopelessness, self-abasedment and gastrointestinal symptoms were significantly higher in IBS-C patients than that in FC patients (P < 0.05). For IBS-C (χ² = 5.438, P < 0.05) but not FC, patients with normal colon transit time were significantly more likely to have anxiety than those with slow colon transit time. For IBS-C patients but not FC patients, the threshold of first constant sensation, desire to defecate and sustained urgency were all weakly correlated with the degree of anxiety (r = 0.414, r = 0.404, and r = 0.418, respectively, P < 0.05). The proportion of patients with a low threshold of desire to defecate among IBS-C patients with depression was lower than that in those without depression (69.6% vs 41.9%, χ² = 4.054, P < 0.05).

Our findings highlight both overlapping and distinctive patterns of colon transit, dyssynergic patterns, anorectal sensation, psychological distress, and associations of psychiatric and colorectal motility characteristics in FC and IBS-C patients in an Eastern Chinese population, providing valuable insights into the pathophysiological underpinnings of these disorders.