The authors report two cases of a peculiar microphlebitis of the intestines, similar to that described by Saraga and Costa quite recently [5]. The patients had undergone hemicolectomy because of evolving ileus caused by cecal polyps or lipohyperplasia, respectively. Pseudomembranous-ulcerative inflammation of the cecum and variously intense lymphocytic infiltrates of numerous small submucosal veins and venules of the intestines were found in both cases. Thrombosis occurred very rarely in the affected vessels, although sometimes it was found in deeper and larger veins. Arteries, lymphatics, mesenterial veins and lymph nodes were normal. Parts of the distal ileum and ascending colon displayed the phlebitic changes without mucosal alterations. The authors hypothesize that it was not the abnormal local circulation, but some hitherto not fully clarified immunological disorder that resulted in the disease. In contrast to the claim of Saraga and Costa [5], it is suggested that thrombosis of the small veins does not have a significant role in the development of the lesions, but a complex process that includes the entry of antigens via the altered mucosa followed by an immunogenic inflammatory response of the small veins is responsible for the pathogenesis.