The preferred bypass procedure in case of non resectable carcinoma of head of pancreas is
High-Yield Explanation
It is preferable to use bile duct rather than the gall bladder.Cholecystojejunostomy is easier to perform,but the bile must then drain through the cystic duct,which is narrow and ,if the cystic duct is inseed low into the bile duct,it is vulnerable to occlusion by tumour growth. Bailey & Love 26th edition ,page no.1140 .