Authors report their experience about neoplastic large bowel obstructions and present two cases of anastomotic leakage resolution by means of transtomy wash-out. They observe that the most important problem in this surgery is anastomotic leakage which, if small, can be solved in a non operative way. According with literature, they also point out anastomotic leakage is commonly due to the impossibility of a correct preparation of colon to operation in emergency. They conclude it is possible, in case of little leakages, to perform trans-stomy wash out which permits a good toilette and sterilization of the colon.