Initially, we tried injecting with two sclerotherapy nee- dles passed through a two-channel colonoscope, one for saline solution injection to create a submucosal bleb and another for India ink injection into the saline bleb. Recently, we have been using only one sclerotherapy nee- dle to inject saline solution followed by India ink. After each tattooing, the needle is withdrawn from the colono- scope and the ink is flushed out with saline solution until the effluent is clear before creation of a second bleb with saline solution to avoid obscuring the field with ink. With this double injection technique, we have been able to tat- too the colon successfully without any extravasation of the dye (confirmed at laparotomy). Although we believe that this technique is safe and avoids the risk of contamination of the peritoneal field during tattooing, it needs to be test- ed in animal experiments. Gottumukkala S. Raju, MD, DM, MRCP Department of Medicine Kansas University Medical Center Kansas City, Kansas REFERENCE 1. Alba LM, Pandya PK, Clarkston WK. Rectus muscle abscess associated with endoscopic tattooing of the colon with India ink. Gastrointest Endosc 2000;52:557-8. doi:10.1067/mge.2001.112719 A wire-loop technique for removal of embedded biliary stents To the Editor: I read with a great deal of interest the case report by Drs. Amann and Somogyi, 1 dealing with the not-uncommon problem of biliary stent migration. In the technique described by these investigators, once the snare and guidewire combination is secured around the migrated stent, it is pulled into the stomach along with the duo- denoscope. Depending on the degree to which the stent is embedded into the mucosa, I would be concerned that this technique may cause considerable damage to the duode- nal mucosa. Apparently the authors have had no major complications. The usual grasping devices used to secure the stent, such as the rat-tooth forceps, are often not help- ful, especially with large-diameter stents. In addition, the rat-tooth forceps used by most endoscopists is fairly stiff and not meant to be used via duodenoscopes and thus can damage the elevator mechanism on these endoscopes. I have been successfully using a rotatable stent-retrieving forceps (FG-44NR-l; Olympus America Inc., Melville, N.Y.) to secure the stent, push it into the bile duct (getting the end out of the duodenal wall), and removing it through the accessory channel of the duodenoscope. The fact that you can rotate the tip of this forceps assures that you will ori- ent the grasping end of the forceps perpendicular to the stent, avoiding frustration and wastage of time. Also, this latter forceps is designed to be used via a duodenoscope. Irshad H. Jafri, MD Regions Hospital St. Paul, Minnesota REFERENCE 1. Amann ST, Sornogyi L. A wire-loop technique for removal of migrated and embedded biliary stents. Gastrointest Endosc 2000;51:485-6. doi:10.1067/mge.2001.114415 Response: We appreciate the comments of Dr. I. H. Jafri regarding the wire loop technique 1 to remove migrated biliary stents. A concern raised was the potential trauma to the duo- denal mucosa/wall as the embedded stent is removed. Fortunately, no further significant mucosal injury has been noted and the goal of stent removal is to prevent per- foration. Some minor trauma occurs as the stent is removed but because the force is parallel and outward rel- ative to the duodenal wall, the theoretical risk of trauma with resultant perforation is low. A variety of tech- niques 2,3 have been described to remove distally migrated and embedded stents, and Dr. Jafri describes another use- ful technique. Certainly the rotatable stent retrieving for- ceps (Olympus America, Inc.) appear to offer two advan- tages: the ability to grasp even the larger stents and the ability to reposition the stent within the duct to allow removal with a standard snare. This adds another option to the therapeutic endoscopist’s armamentarium for the treatment of migrated biliary stents. Stephen T. Amann, MD North Mississippi Medical Center Tupelo, Mississippi Lehel Somogyi, MD University of Cincinnati Cincinnati, Ohio REFERENCES 1. Amann ST, Somogyi L. A wire loop technique for removal of migrated and embedded biliary stents. Gastrointest Endosc 2000;51:485-6. 2. Mergener K, Baillie J. Retrieval of a distally migrated, impacted biliary endoprosthesis using a novel guidewire/bas- ket “lasso” technique. Gastrointest Endosc 1999;50:93-5. 3. Smith FCT, O’Connor HJ, Downing R. An endoscopic tech- nique for stent recovery used after duodenal perforation by a biliary stent [letter]. Endoscopy 1991;23:244-5. doi:10.1067/mge.2001.114913 Oral preparations for flexible sigmoid- oscopy To The Editor: We read with interest the study in a recent issue of Gastrointestinal Endoscopy by Bini et al., 1 which com- pared an oral preparation to a typical enema-based regi- men used for flexible sigmoidoscopy. Using a predomi- nantly male study population, they showed the use of oral phospho-soda produced a superior quality of preparation and better patient tolerance compared with 2 enemas. Letters to the Editor 698 GASTROINTESTINAL ENDOSCOPY VOLUME 53, NO. 6, 2001