Rectal intussusception in symptomatic patients is different from that in asymptomatic volunteers

Rectal intussusception is a common finding at evacuation proctography in both symptomatic and asymptomatic individuals. Little information exists, however, as to whether intussusception morphology differs between patients with evacuatory dysfunction and healthy volunteers.

Thirty patients (19 women; median age 44 (range 21-76) years) with disordered rectal evacuation, in whom an isolated intussusception was seen on proctography, were studied. Various morphological parameters were measured, and compared with those from 11 asymptomatic controls (six women; median age 30 (range 24-38) years) found, from 31 volunteers, to have rectal intussusception. Intussusceptum thickness greater than 3 mm was designated as full thickness. Intussuscepta impeding evacuation were deemed to be occluding.

Twenty-two patients had full-thickness intussusception, compared with two controls (P = 0.003). Intussusceptum thickness was significantly greater in the symptomatic group (anterior component: P = 0.004; posterior: P = 0.011). Twenty patients in the symptomatic group, but only three subjects in the control group, had a mechanically occluding intussusception (P = 0.043), although only three patients demonstrated evacuatory dynamics outside the normal range.

Rectal intussusception in patients with evacuatory dysfunction is more advanced morphologically than that seen in asymptomatic controls; it is predominantly full thickness in patients and mucosal in controls. However, caution is required when selecting patients for intervention based solely on radiological findings.