fecal microbiota transplantation ( fmt ) has gained worldwide attention in recent years 1 . in 2013 ,
it was recommended as the clinical choice in guidelines for treatment of recurrent clostridium difficile infection ( cdi ) 2 .
in addition , clinical studies have shown that fmt has a therapeutic role in inflammatory bowel diseases , refractory constipation , chronic diarrhea , and metabolic syndrome 3 
 4 . since 2012
, our group has been evaluating possible applications for and new methods of applying fmt 5 
 6 
 7 .
previous reports on fmt for delivery of treatment have involved the upper , middle , and lower gut 8 
 9 
 10 
 11 .
fmt via colonoscopy is a classic approach , but patients have to endure bowel preparation and colonoscopy , especially when they need repeat treatment over a short period of time 12 .
a traditional enema delivers solution only within the rectal and sigmoid colon which is way , in our previous studies of crohn s disease and ulcerative colitis , why we chose to use fmt for delivery through the mid - gut 6 
 7 .
however , patients may find it psychologically difficult to accept fmt through the upper and middle digestive tract .
importantly , reflux and aspiration of bacterial liquid may occur and even cause asphyxia 13 
 14 .
there is currently no technique for placing a tube through the anus into cecum for whole - colon administration of treatment that could be maintained for repeat fmts or while awaiting fresh fecal microbiota from the lab .
therefore , to solve these problems , we designed a new technique called transendoscopic enteral tubing ( tet ) .
as shown in fig .  1 , the tet tube is fixed to the cecum with clips under endoscopic guidance .  
 concept sketch of fmt treatment by tet .
a prospective observational study ( nct02560727 ) was conducted at the second affiliated hospital of nanjing medical university from october 2014 to september 2015 .
all patients met the inclusion criteria , which were age 10 to 70 years , safety for the pilot study , suitability for endoscopy , and consent to undergo fmt and tet for their diseases and conditions .
patients were excluded it they had severe bowel lesions with stenosis , fistula , or the risk of perforation ; complex perianal lesions or serious lesions in the ileocecal junction or ascending colon ; and no proper site for titanium clip fixation .
the study was approved by the institutional review board of the second affiliated hospital of nanjing medical university .
regular colonoscopy was performed under intravenous anesthesia . after examination and evaluation of the whole colon ,
the tet tube ( fmt medical , nanjing , china ) was inserted into the ileocecal junction through the endoscopy channel ( fig .  2 ) .
the colonoscope was removed from the colon while the tet tube was maintained at the ileocecal junction .
the line circle on the tet tube was affixed to the intestinal wall using titanium clips under direct vision ( generally two titanium clips at the first station and one to two clips at the second and/or third station as necessary ) ( fig .  3 and fig .  4 ) .
the distal tube was affixed to the skin of the buttocks ( preferably on the left side ) with medical adhesive plaster .
a valve was connected to the terminal tet tube . the procedure time and all related adverse events ( aes )
attachment of titanium clips to the tet tube to the cecum mucosa at the first station under endoscopic guidance .
the tip of the guidewire can be seen within the tube . 
 the second station of tet tube attachment in the ascending colon mucosa with titanium clips under endoscopic guidance .
the guidewire can be seen within the tube . according to the concept shown in fig .  1 , the patient was required to be in the right - lateral position and then 200  ml of suspension was injected through the tet tube .
the 200-ml suspension was a mixture of 150  ml saline and 50  cm centrifuged microbiota that was purified following our lab protocol and using the automatic system genfmter ( fmt medical , nanjing ) 6 
 7 .
the duration of the injection was recorded and intended to be more than 1 minute so as to avoid the abdominal discomfort that would be associated with a quicker procedure .
after fmt , patients were required to remain in the right - lateral position for 30 minutes .
retention of the microbiota suspension for over 1 hour indicated successful delivery of the microbiota through colonic tet . in some cases ,
fmt was repeated during subsequent days to ensure infusion of the microbiota to the whole colon .
reports from patients of discomfort during fmt were recorded and all of them agreed to participate in the post - treatment survey on satisfaction with tet and fmt .
a prospective observational study ( nct02560727 ) was conducted at the second affiliated hospital of nanjing medical university from october 2014 to september 2015 .
all patients met the inclusion criteria , which were age 10 to 70 years , safety for the pilot study , suitability for endoscopy , and consent to undergo fmt and tet for their diseases and conditions .
patients were excluded it they had severe bowel lesions with stenosis , fistula , or the risk of perforation ; complex perianal lesions or serious lesions in the ileocecal junction or ascending colon ; and no proper site for titanium clip fixation .
the study was approved by the institutional review board of the second affiliated hospital of nanjing medical university .
regular colonoscopy was performed under intravenous anesthesia . after examination and evaluation of the whole colon ,
the tet tube ( fmt medical , nanjing , china ) was inserted into the ileocecal junction through the endoscopy channel ( fig .  2 ) .
the colonoscope was removed from the colon while the tet tube was maintained at the ileocecal junction .
the line circle on the tet tube was affixed to the intestinal wall using titanium clips under direct vision ( generally two titanium clips at the first station and one to two clips at the second and/or third station as necessary ) ( fig .  3 and fig .  4 ) .
the distal tube was affixed to the skin of the buttocks ( preferably on the left side ) with medical adhesive plaster .
a valve was connected to the terminal tet tube . the procedure time and all related adverse events ( aes )
attachment of titanium clips to the tet tube to the cecum mucosa at the first station under endoscopic guidance .
the tip of the guidewire can be seen within the tube . 
 the second station of tet tube attachment in the ascending colon mucosa with titanium clips under endoscopic guidance .
the guidewire can be seen within the tube . according to the concept shown in fig .  1
, the patient was required to be in the right - lateral position and then 200  ml of suspension was injected through the tet tube .
the 200-ml suspension was a mixture of 150  ml saline and 50  cm centrifuged microbiota that was purified following our lab protocol and using the automatic system genfmter ( fmt medical , nanjing ) 6 
 7 .
the duration of the injection was recorded and intended to be more than 1 minute so as to avoid the abdominal discomfort that would be associated with a quicker procedure .
after fmt , patients were required to remain in the right - lateral position for 30 minutes .
retention of the microbiota suspension for over 1 hour indicated successful delivery of the microbiota through colonic tet . in some cases ,
fmt was repeated during subsequent days to ensure infusion of the microbiota to the whole colon .
reports from patients of discomfort during fmt were recorded and all of them agreed to participate in the post - treatment survey on satisfaction with tet and fmt .
as shown in table  1 , 54 patients were included in this prospective study : 32 males and 22 females aged 10 to 70 years ( mean  sd , 34.5  10.4 ) . of the patients , 23 cases had ulcerative colitis , 16 had crohn s disease , five had unexplained chronic diarrhea , five had constipation , three had small intestinal bacterial overgrowth , and 2 had irritable bowel syndrome .
the mean time from advancement of the tet tube through the channel to the end of the tubing was 14.8 minutes .
three clips were used on two fixation stations of the tet tube in 36 cases during our preliminary observational period or in patients who only needed short - term retention of tet tube retaining . in the remaining 15 cases ,
no complications such as mild to serious abdominal pain and bleeding stool were observed . during the tet tube retention period ,
98.1  % of patients ( 53/54 ) were satisfied with tet ; one patient with ulcerative colitis complained of tolerable mild anal discomfort ; no other patients complained of anal pendant expansion .  
fmt , fecal microbiota transplantation ; tet , transendoscopic enteral tubing ; sd , standard deviation .
a total of 200  ml of fecal microbiota suspension was given to each patient and the mean injection time was 3.2 minutes . in all cases ( 100  % ) ,
fmt through colonic tet was successful . in 88.4  % of cases ( 49/54 ) , patients reported no discomfort during fmt .
one patient ( 1.9  % ) with severe ulcerative colitis complained of abdominal pain after infusion through tet tube , and the symptoms were alleviated with rest .
four patients ( 7  % ) reported tolerable mild abdominal distension . in one case , we encountered difficult with the infusion because of bending of the tube at an angle in the intestines , which was resolved with injection of normal saline at high pressure .
the time from the end of the fmt to the first defecation was 6.3  0.7 hours . in 35 patients with ulcerative colitis or crohn s disease
mesalazine was delivered daily to them through the tet tube until the tube fell off .
the retention duration was 12.4  2.3 days . in 19 patients , removal of the tet tube
reports exist of use of fmt to deliver treatment to the upper gut , mid - gut and lower gut .
the capsule dissolves in the small intestine and bacteria are distributed in the gastrointestinal tract . in mid - gut ,
the microbiota suspension is injected into the small intestine below the second duodenal segment under endoscopic direct vision or via a nasogastric tube , small intestine stoma or percutaneous endoscopic gastrostomy with jejunal extension ( pegj)15 .
fecal microbiota can be delivered to the lower gut through colonoscopy , enema , distal ileum stroma , colostomy , and colonic tet .
the advantages and limitations of different methods of delivering fmt are shown in table  2 .
fmt : fecal microbiota transplantation ; pegj : percutaneous endoscopic gastrostomy with jejunal extension ; sibo : small intestinal bacterial overgrowth ; tet : transendoscopic enteral tubing . in this study ,
tet and fmt were successfully performed in all 54 cases ( 100  % ) , and fmt retention time was longer than 1 hour .
this tet technique and the novel tet accessary devices used demonstrate the feasibility and significance of colonic administration .
no serious aes were observed during the tet procedure , infusion of fmt through the tet tube , the period during which the tet tube was left in place , or removal of the device . during the fmt procedure ,
the mean retention time for the microbiota suspension was enough to meet the requirement for fmt according to our protocol . for patients who required repeat fmt and combined colonic administration of mesalazine , it was a convenient and economic way to use the colonic tet tube .
importantly , this method may be less psychologically challenging for patients than delivery of fmt via the upper and middle digestive tract .   in 19 patients ,
the tet tubes were removed after a single fmt or colonic administration . of them , 4 with ibd required removal of the tet tube after fmt and 1-week administration of mesalazine ( 7 enemas in a single package of salofalk ) because there was no need to leave the tet tube in place . according to our lab protocol and clinical flow 6 
 7 , for consideration of improving possible clinical efficacy ,
the time from defecation of stool to infusion of microbiota was required to be no more than 1 hour .
therefore , 15 patients agreed to the use of tet while waiting for fresh microbiota from the lab and because they preferred psychologically delivery through the lower gut , and their tet tubes were removed after fmt .
it should be emphasized that the patients daily lives were not affected by tet , and in 98.1  % of cases ( 53/54 ) , they were satisfied with fmt through tet . for patients with ulcerative colitis that involved the entire colon or crohn s disease
, tet should be a wonderful choice for frequently delivering medication into the whole colon . in the current study ,
all 23 patients with ulcerative colitis and 16 patients with crohn s disease were administered a mesalazine enema through the tet tube . of them , six patients were discharged with the tube and they were able to conveniently infuse medication by themselves at home .  
besides this pilot study on colonic study for whole - colon administration through a colonic tet tube , a study on the similar concept of tet used for interventional therapy by duodenal or jejunal tet under gastroscopy is ongoing in our center .
the sample size of this pilot study was small , but a larger prospective study based on these preliminary results is ongoing .
this study did not evaluate clinical responses to whole - colon administration compared with other traditional treatments ; that will be part of our future studies .
a cost - efficacy analysis is necessary and the results may vary from country to country depending on policies for medical charges .
patients who require only a single fmt ( e.  g. cdi ) may not need to generally may not need to undergo colonic tet if use of fresh fecal microbiota is not a consideration and that is why there were no cdi patients in this study . in conclusion , this study is the first report of colonic tet as a convenient and safe way of delivering fmt .
the results highlight the significance of colonic tet as a promising technique for single and repeat whole - colon administration of medication .
 
 background and study aims : placement of a tube through the anus into the cecum has not yet been established as a method of administering whole - colonic treatment . 
 the aim of this study was to evaluate the safety , feasibility , and value of transendoscopic enteral tubing ( tet ) for fecal microbiota transplantation ( fmt ) through the colon . 
 
 patients and methods : a prospective observational study was performed of fmt using a new colonic tet technique . under endoscopic guidance , a tet tube was affixed to the cecum with clips . the safety , value , and satisfaction with the fmt by tet were evaluated . 
 
 results : a total of 54 patients underwent tet . 
 the success rate of the tet procedure was 100  % ( 54/54 ) . 
 duration of the tet procedures was 14.8    5.8  min . during the tet tube retention period , 98.1  % ( 53/54 ) of patients were satisfied with tet . 
 the retention time for whole - colon delivery of the fecal microbiota suspension was 12.4    2.3 days . in 88.4  % ( 49/54 ) of cases , no discomfort was reported during injection through the tet tube of the microbiota suspension . 
 no adverse events were see in patients who required tube extubation after fmt . 
 
 conclusions : colonic tet is a novel , safe , convenient , and reliable procedure for fmt that results in a high degree of patient satisfaction . 
Introduction
Patients and methods
Subjects
Preparation, procedures and assessment of TET
Results
Discussion