1) Seven types of irritation causing intestinal adhesions are recognized in the literature : namely, a) mechanical injury; b) chemical injury; c) thermal injury; d) bacterial infection; e) foreign body; f) blood; and g) exsiccation. Certain minor differences of opinion exist among investigators, according to the experimental methods and the experimental animals used, and blood is not universally accepted as a cause of adhesions. The author believes, however, that the above list includes all of the etiological factors so far recognized in the literature. 2) The mechanism of intestinal adhesions is similar to that of wound healing. The problem of fibre synthesis is still unsolved, despite many advances in electlon microscopy, histochemistory and X-ray analysis. In recent years it has been accepted that fibres are synthesized in extra-cellular space from cytoplasmic materials derived from either mesenchymal cells or fibroblasts, and from polysaccharides in ground substances, althoughth eexact kind of polysaccharides which plays an important role in this process is still unknown. 3) Many papers are recognized with the prevention and treament of adhesions. These may be devided into six groups according to the method suggested: a) limitation of the original peritoneal injury; b) prevention of the coagulation of the exudate; c) avoidance of prolonged contact between the injured surfaces; d) removal of the fibrin after its formation; e) stopping or slowing down of the proliferation of fibroblasts; f) prevention of further obstruction by means of controlling the area of damaged intestine in stepladder fashion, the so-called the plication method. 1. It is the common practice of surgeons to limit the original peritoneal lllJury by laparotomy. Experimental studies have demonstrated that peritonealization of an area denuded of serosa often results in more extensive adhesions. 2. To prevent coagulation of the exudate, Lehman and Boys and other investigators used heparin and dicumarol. The role of heparin in the prevention of adhesions may be summarized as follow: there is a short time interval separating the production of the exudate and its subsequent coagulation with the deposition of fibrin on injured serosal surfaces. Anticoagulants of various types should be effective in preventing this fibrin formation if it is assumed that the coagulation mechanism of both exudate and blood is the same. Though the use of heparin and dicumarol has demonstrated a preventive effect on adhesion formation in experimental animals, many surgeons believe that the risk of hemorrhage from heparin and dicumarol outweighs their possible benefit in the prevention of adhesions. 3. To prevent prolonged contact between injured surfaces, amnion, omental and mesothelial graft, and so on, have been used without success. The stimulation of peristalsis by means of prostigmin and early feeding, however, appears to be effective in the prevention of adhesions, although its use in clinical cases has not been reported. 4. The experimental data indicates that streptokinase alone has no preventive effect on the formation of adhesions, because fibrinolysis is facilitated only by the existence of activated human plasmin. Concernig the use of hyaluronidase, this is an enzyme with the property of hydrolyzing hyaluronic acid, one of the polysaccharides that constitutes the intercellular ground substances. Experimental studies on the use of this material indicate, in summary, that topically administered hyaluronidase reduces the number of adhesions and particularly their density. The reason why hyaluronidase is effective in the prevention of adhesions is still unknown. 5. The use of corticoids and ACTH, according to all available experimental data, appears to delay the formation of adhesions and to prevent talc-induced adhesions, possibly by increasing the absorption of talc. In administrating corticoids, however, their tendency to delay wound healing, to perforate the intestinal wall, and to induce hemorrhage must be taken into account. 6. Experimental study and clinical USe of the plication method demonstrate that in patients with severe recurrent adhesions, or in those for whom the afore-mentio ned methods have been ineffective, this procedure is probably the most effective therapy available.