Defecatory disorders in patients with type 1 diabetes and chronic constipation

Chronic constipation (CC) may be caused by defecatory disorders (DDs) and associated with reduced rectal sensation. Among patients with type 1 diabetes (T1D) and CC (T1DCC patients), the prevalence of DDs and reduced rectal sensation is unknown. We sought to compare complications of T1D, anorectal dysfunction, and CC symptoms, among T1DCC patients with versus without a DD.

Anorectal pressures at rest and during squeeze and evacuation, as well as rectal sensation and rectal balloon expulsion time (BET) were measured with high-resolution anorectal manometry in 114 consecutive T1DCC patients.

Thirty-seven patients (32%) had prolonged BET, suggestive of a DD. Complications of T1D included peripheral neuropathy (n = 67, 59%), retinopathy (n = 42, 37%), and nephropathy (n = 26, 23%). Among these complications, only retinopathy was associated with, that is, more prevalent in patients with normal (45%) than prolonged BET (19%). Compared with patients with normal BET, patients with prolonged BET had a lower rectal pressure (mean [SD], 32 [23] mm Hg vs. 23 [19] mm Hg, p = 0.03), greater anal pressure (91 [23] mm Hg vs. 68 [36] mm Hg, p < 0.001), and lower rectoanal gradient (-67 [30] mm Hg vs. -36 [32] mm Hg, p < 0.0001) during evacuation. Anal resting pressure and anal squeeze increment were below normal in 14 (13%) and 32 (29%) of patients and one or more rectal sensory thresholds were above normal in 34 (30%) patients; these abnormalities affected similar proportions in the normal and prolonged BET cohorts.

Among T1DCC patients, 37 (32%) had prolonged BET, which was associated with anorectal pressures indicative of a DD but was not associated with reduced rectal sensation, suggesting that DDs are more likely explained by abdomino-anal dyscoordination than visceral disturbance.