Tropical intussusception in adults.

In contrast with the incidence in Britain and the United States, about 50% of intussusceptions in Sri Lanka occur in adults, the maximum age incidence being in the fourth decade. Seventy-six cases of intussusception in adults are analysed in this paper, 62 of which were of the caecocolic type, which though only rarely described in the West, have also been frequently reported from other tropical countries. The clinical picture was characteristic, and a mass was palpable in 90% of the patients, facilitating diagnosis without ancillary investigations. On the basis of the histological examination of resected specimens it is concluded that amoebic granulomatous formation in the dependent "diverticulum" of the caecum is the predisposing cause of the caecocolic intussusception, accounting for the chronicity of a large number of cases. Irrespective of the duration of the illness, gangrene did not occur in any of the cases if this type, although resection was occasionally required on account of irreducibility. In view of the proliferation of fibrous tissue in the wall of the caecum, complete evagination of the intussusception can only be achieved by surgical exploration and manipulation, the results of which are excellent.