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

Background: 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. Methods: 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 nun was designated as full thickness. Intussuscepta. impeding evacuation were deemed to be occluding. Results: 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. Conclusion: 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.