Choledocholithiasis is a common gastrointestinal disease which can lead to severe conditions including death. According to the proven role of opioids in the spasm of Oddi's sphincter, which causes Biliary stasis in common bile ducts, it is probable that opioids can also increase the incidence of Choledocholithiasis. In this regard, we have studied the prevalence of opium addiction in patients with Choledocholithiasis.

We performed a retrospective study of 559 patients with Choledocholithiasis who undergone ERCP using data collected, at the Qaem hospital of Mashhad in Iran from 2011 through 2015. Using files and records, we gathered patient's data which includes, gender, opium addiction, and level of hepatic enzymes (AST, ALT, ALP, Bill T, D). The coincidence of gallbladder stones and CBD stones and the size of CBD stones were calculated.

Of the 599 patients included, 254(42.4%) were men and 345(57.6%) were women.195 patients (32.2%) were addicted to opium. There was a positive correlation found between the CBD stone size and patients age (r=0.17, p=0.001). The mean stone size was12.22±3.32mm. The mean CBD stone size of addicted cases was 12.71±5.13mm while it was12.3±4.33mm in non-addicted cases.

We have found that the prevalence of opium addiction is more common in patients with CBD stone when compared with general population indicating the probable relation between opium addiction and CBD stone formation.