R-Y Gastric Bypass (RYGB) Revisions

Gastric Bypass (RYGB) is one of the most popular bariatric surgery, especially after the decline of Adjustable Gastric Banding globally. It shares the throne with Sleeve Gastrectomy in the last decade.

Gastric Bypass (RYGB) is almost 100 % a restrictive operation. It functions to limit the amount of food that can be consumed at a time. However, as it bypasses the whole duodenum, it has a prominent effect on supression of foregut anti-incretin response of the body. This metabolic effect is significant in control of diabetes especially in morbidly obese, with volume restriction.

Gastric Bypass (RYGB) is highly prone to deformation of pouch and the gastrojejunal (G-J) anastomosis. When this happens, the patient starts to feel hunger and realises that the volume of meals increase. The weight regain can easily happen in a short period of time.

Revisional Surgery for weight regain after Gastric Bypass (RYGB) will be one of the most important and complicated issues of the next decade, as the Gastric Bypass (RYGB) numbers increase every year. Especially conversions to other bariatric procedures such as Duodenal Switch, are extremely complicated, many surgeons also tend to prefer Sleeve Gastrectomy rather than Gastric Bypass (RYGB) for morbid obesity.

Recent studies Show comparable weight loss results with sleeve gastrectomy and RYGB. Incoming years most probably we will see the rise of sleeve gastrectomy all over the World to be the most prefered bariatric surgery.


Why does RYGB Patients Regain Weight?

Altough having a metabolic effect to supress the foregut anti-incretin response; still RYGB is almost 95 % a restrictive operation. The bypassed jeunum and duodenum is less than 10 % at most; insufficient to limit the calorie absorption. When high calorie nutrion is present, such as sweets, fat rich meals, starch etc.; no limitation of absorption takes place, and patients may regain weight, though functioning volume restriction.


The Facts of Gastric Bypass (RYGB)


Gastric Bypass (RYGB) decreases feeling of hunger temporarily, and it comes back in time!

Gastric Bypass (RYGB) is a restrictive surgery. The amount of meal at a time does not usually exceeds 40-50 cc. This extreme restriction, ends with great amount of weight loss at the first year. This period may last to one and a half to two years which is called “the honeymoon period” as in all obesity operations. The feeling of hunger is thought to be controlled in a way with a gut-brain hormone; Ghrelin. Ghrelin is a pro-meal apetite stimulating hormone mainly produced at fundus of stomach. It is more easy to understand the promt decrease in ghrelin levels when fundus is resected in sleeve gastrectomy. Also, many researchers reported significant decrease in ghrelin levels after gastric bypass. However there are other reports which do not observe ghrelin decrease with gastric bypass. So the decrease of ghrelin after gastric bypass is controversial and not always directly related with weight loss when present.

The Gastric Bypass, however, still has something more than a restrictive surgery. This is not the ghrelin fluctuation but the elimination of food transit from duodenum. This changes the apetite sense only when the restriction functions efficiently. This is quite easy to observe cause patients who regain weight mostly loose their restrictive control with pouch and G-J deformations; still have their foreguts away from nutrional stimulation. But this time the foregut hypothesis does not work enough to tolerate the pouch enlargement or anastomotic dilatation.


Also the increased food transit to jejunum, promotes earlier delivery of food to distal ileum to stimulate the satiety hormones GLP-1 and PYY. GLP-1 is strongly stimulated by RYGB, so that in some cases  benign tumor-like lesion forms in pancreas beta cells called nedisioblastosis. This strong GLP-1 response maybe interpritted as “un-controlled”, “imbalanced” or “exeggerated” even “over-extended” insulin response to refined carbs like sweets. Many RYGB patients have Dumping Syndrome to keep them away from sweets. However, the “un-controlled”, “imbalanced” or “exeggerated” even “over-extended” insulin response to refined sugary meals, lead patients to “hypoglycemia” which ends up with craving for more sweets. This closed-loop circuit, together with dumping syndrome’s vomitting attacks, results with deformation in the magical “golden ratio” of the pouch/anastomotic dimensions and weight-regain.


The basic difference between RYGB and  Duodenoileal Interposition is the stimulation pattern of ileal hormones. RYGB has mostly an uncontrolled response leading to postprandial hypoglycemia. However Duodeileal Interposition has the control of the whole stomach with functioning pylorus, altough it stimulates even the very distal ileum when compared to RYGB. These anatomical advantages in both ways, forms a better physiologic GLP-1 response to meal which leads to hormonal satiety without any dumping syndrome and restore a balanced first phase insulin  response to even sugar comparable to non-diabetic healty people.


Every Restriction Deforms: Every RYGB Pouch Enlarges

The capacity of the pouch of RYGB  (40-50 cc) is incomparably low to normal stomach capacity (1000-1500 cc). This tiny pouch extremely limits the amount of solid food that can be taken at a time. Even the liquids in slightly bigger amounts increase the intraluminal pressure of the tiny pouch. So the RYGB pouch can be interpretted as a continuously “High Pressure” area.

This high pressure zone dynamics, limits the food intake to great extend and RYGB patients can loose to 60-70 % of excess weight in 1-2 years. However, the streching of the pouch in almost every bite and the vomitting attacks of dumping syndrome lead to enlargement of the pouch and dilatation of gastrojejunal anastomosis.

Even an increase from 50 cc to 80-100 cc can esily ends up with weight regain cause there is no pylorus valve to control the outlet of stomach. With a slightly increased pouch, many of the RYGB patients start to feel hunger and regain weight. 



FACT:              Gastric Bypass (RYGB) needs your “lifetime” commitment to be away from sugar, starch and fats!


MYTH:             “You are a Sweet Eater! We will do RYGB to keep you away from sweets!”




Let’s go over the Dumping Syndrome to see how gastric bypass will change your relationship with sweets.


What is Dumping Syndrom?

Dumping syndrome after gastric bypass surgery occurs due to rapid transit of  undigested food which gets dumped directly from the pouch to jejunum without a control barrier of pylorus muscle. The main reason is the absence of pylorus.

As the food goes directly and quickly into jejunum, the intestines face suddenly a dense content and respond with incretins to change the fluid balance in order to accumulate serum in the jejunum lumen. This significant accumulation of fluids happens as a fluid shift from intravascular compartment to intraluminal area.

As a result the intestines distend, gets fuller and bloated. Besides abdominal distension, the significant and rapid shift of fluids from intravascular compartment leads to rapid decrease in blood pressure; leading to painful vomiting that sometimes ends up with fainting.

There are 2 types of dumping syndrome: early and late. Early dumping happens 10 to 30 minutes after a meal. Late dumping happens 1 to 3 hours after eating.

We have already explained the early dumping symptoms.  Symptoms of late dumping are totally related with post prandial hypoglycemia,  a decrease in blood sugar level (reactive hypoglycemia). Reactive hypoglycemia is low blood sugar caused 1 to 3 hours after a large surge of insulin. Patients are more likely to have dumping syndrome if they have a starch and sugar rich meal. The sugars can be either fructose or table sugar (sucrose). The “uncontrolled”, “imbalanced” or “exegerated” even “over-extended” insulin response  lowers the blood glucose to life treathening levels. 


What are the symptoms of dumping syndrome after gastric bypass surgery?

Most people have early dumping symptoms. Typical early dumping symptoms can include:



            Abdominal cramps and pain


            Facial flushing

            Stomach growling or rumbling

            An urge to lie down after the meal

            Heart palpitations and fast heartbeat

            Dizziness or fainting


About 1 in 4 people have late dumping symptoms. The symptoms of late dumping syndrome can include:

  • Heart palpitations
  • Sweating
  • Hunger
  • Confusion
  • Fatigue
  • Aggression
  • Tremors



The False Statement:

A patient who experience dumping syndrome stays away from sugar!


This statement may be true to some extend. At the early periods of gastric bypass surgery, dumping can be strong and tiring for patients to keep them away from sugar. But dumping does not happen only with sugar. So as the patient starts to have dumping, he/she face reactive hypoglycemia, not very serious at every time but significant enough to crave for sugar. As the time pass, if the patient can not strictly control the dumpings, then sugar intake will increase and vomitting attacks become frequent till the moment that the pouch and anatomosis dilates to decrease the dumping. This release of mechanical restriction, leads to re-immergence of hunger and increase the portions of meals.

The food passing trough the pouch is 100 % absorbed in gastric bypass. This leads to significant weight regain and co-morbidities like diabetes come back.





When Should a Revision/Conversion be Considered after Gastric Bypass?


  1. Weight Regain

Weight regain after gastric bypass can be even more than its assumed.

Failure is defined according to Reinhold Classisfication as the nadir BMI being over 35 kg/m2 and maximum excess weight loss less than 50 %.

The failure of weight loss or weight regain after gastric bypass is mostly related with pouch and/or anastomotic dilatation.

Gastric Bypass have weight regain rates ranging between 20-35 % in morbidly obese patients. If the super obese is considered this weight regain ratio might come up to 58 %.

The first step for evaluation is the barrium swallow x-ray and diagnostic endoscopy. The pouch and the anastomosis are visualised. In some cases oral contrast inhanced upper abdominal CT is used to tree diamentionally schematise the pouch and the G-J anastomosis.


  1. Reactive Hypoglysemia

Post prandial reactive hypoglycemia is a lifetrethening significant complication that seriously lowers the quality of life also. The primary reasın of this is the lack of pyloric control at the gastric outlet. Without pylorus, the jejunum becomes quickly exposed to gastric content.

The main treatment is to get pylorus in to action. Its to restore the gastric contiunity, to cut it short. This can be done as revision to normal anatomy without any further resection. This has the risk of weight regain. Other options of conversion to different bariatric or metabolic surgeries are decided with the patient, considering the highest BMI before bypass.

Our team is experienced on Duodenal Switch (for super obesity) and Duodenoileal Interposition/Gastroileal Interposition (morbid obesity and below) as a conversion surgery.


  1. Severe Dumping Syndrome

Dumping Syndrome is not always an indication for conversion of gastric bypass to another type of pylorus preserving surgery. Because its at the same time the mechanism of action for gastric bypass (RYGB). However, some patients may suffer from dumping more than 4-6 times a day. If the patient feels tired of this, or if these ongoing dumpings prevent enough nutritional support than a conversion should be on the table. A pylorus preserving Duodenal Switch (for super obesity) and Duodenoileal Interposition (morbid obesity and below) as a conversion surgery is our choice. 


  1. Disphagia, Regurgitation, Vomitting

The gastrojejunostomy sometimes be strictured to cause diaphagia and regurgitation. Endoscopic view is important and an endoscopic balloon dilatation can be a minimally invasive option. However, endoscopic interventions do not work well againts fibrosis and are most likely to fail. For many of G-J strictures, laparoscopic resection of anastomosis and reconstruction of a new one is the best option. I do prefer to do a hand-sewn gastrojejunostomy to ensure the diameter.


Types of Revision/Conversion Surgeries for Gastric Bypass

  1. Endoscopic Plication of Pouch and G-J Anastomosis
  2. Laparoscopic Pouch Resection
  3. Laparoscopic Gastrojejunal Sleeve Resection (Pouch and Roux Limb)
  4. Distal Placement of Biliopancreatic Limb
  5. Distal Placement of Roux Limb
  6. Conversion to Laparoscopic Sleeve Gastrectomy
  7. Conversion to Laparoscopic Duodenal Switch
  8. Conversion to Laparoscopic Transit Bipartition
  9. Conversion to Laparoscopic Duodenoileal Interposition
  10. Conversion to Gastroileal Interposition


  1. Endoscopic Plication of Pouch and G-J Anastomosis

There are new technical innovations that can endoscopically put stitches to stomach mucosa. The enlarged pouch and anastomosis can be re-shaped with plicating from inside. However the results are not as good as patients need as in seen in several studies. Moreover the relaps of poch enlargements and weight regains are in very high rates. The economical issues seem to be other obsticles for these treatments to gain wide acceptance.

Its seen that most of the stitches are placed only to mucosal folds due to limitations of endoscopy itself and do not form any significant restriction.


  1. Laparoscopic Pouch Resection

This is the best treatment for obvious pouch enlargement. Its slightly more easier when compared to other conversion surgeries. The success rate is favorably higher than endoscopic plications an deven more cot effective. However, studies show thatbthe duration of pouch resections are less then 1 year. Weight regains are risk again for these procedures.


  1. Laparoscopic Gastrojejunal Sleeve (Narrowing of gastric pouch and proximal jejunum)

Many surgeons face anastomotic dilatation and also jejunal dialtation with pouch enlargement. Gastrojejunal Sleeve seems to solve all of these tree issues together. But surgery theatre is not always as we imagine.

Besides the sevre adhesions, mostaly we see that the mesentery of roux limb lies on the left side in continuation with pouch. Putting in a bougie and firing stapler can not be possible in this occasion. Otherwise the vascular source of roux limb may be comprimised and necrosis may be seen.

Some teams may prefer to make an anterior gastrojejunal sleeve. This is more prone to twisting and strcture formation.

The experience of the surgeon is important in revision surgery because any previous plan can be modified or completely changed due to the surgical situation that is clearly present at the operation. Sometimes the surgery might need further steps than planned. Then it should be ended and the situation should be discussed with the patient in detail if all options were not on the table before, according to the new findings.


  1. Distal Placement of Biliopancreatic Limb

Its one of the most recommended revision option for a gastric bypass failure or weight regain. Surgeons mostly believe that, a distal biliopancreatic anastomosis will give better weight loss results.

Unfortunately this modification mostly do not give the expected weight loss result. Even in patient whom had very distal anastomosis, almost 50-100 cm to colon, may not have weight loss but severe diarrhea instead.

The main confusion is, in generally, that the point that bile meets food is important for absorption. That’s why if the bile is diverted to very distal parts of ileum, then there should be less absorption. This is not true in practice. Actually it can not be true also theoretically:

The nutrients need degradation to be a fully absorbed. Especially fats need biliary salts to become fatty acids for absorption. In that means, biliary diversion can comprimise to some extend fat absorption. But this is not enough for weight loss, only causes juicy stool or diarhea!

Leaving a long alimentary limb, bypassing only 50 cm of jejunum and diverting the biliopancreatic limb to the end of alimentary limb does not give weight loss. Because almost 95 % of bowels starting from G-J anastomosis all the way down to begining of large intestines, the food has a long way to be absorbed. The distal diversion of bile does not limit caloric absorption, but stool becomes more fat rich and frequency increase.

The basis to change the absorptive capacity, is first of all, to have an idea about the total bowel length of each spesific patient. Without knowing the total bowel length, the proper ratio can not be decided. The aim should be lengthening the biliopancreatic limb at least to some extend. This can be achieved by Distal Placement of Roux Limb.


  1. Distal Placement of Roux Limb

The transection of biliopancreatic limb and place the B-P limb distally seems more easy and practical for many bypass surgeons as its mentioned above. However this manevour does not change the absorptive length of intestines.

To change the absorptive length, the bypassed section of jejunum should be increased. For this, the jejunojejunal anastomosis is preserved but the allimentary (Roux) limb is transected just before this connection. As a second step a new anastomosis is performed, to a place more distal to jejunojejunal (B-P) anastomosis, which should be adjusted according to whole bowel length, patients degree of obesity and co-morbidities.

Again the limits of this technique should be remembered! If only Roux distalisation will take place, surgeon should remember the limitations of the gastric pouch. So we do not intend to perform very distal placements otherwise, the capacity of the “enlarged” gastric pouch may not be enough to balance the newly formed malabsorptive state. This may cause severe protein energy malnutrition. If potent malabsorption is needed, (in super obese patients),  than conversion to Duodenal Switch should be planned at the first stake.


  1. Laparoscopic Conversion to Sleeve Gastrectomy

Conversion to Sleeve Gastrectomy can be done if dumping is the issue for the patient. Weight regain is not an contrindication cause, a functioning pylorus is a good tool for prolonged satiety. If weight regain is due to pouch enlargement, the excess part will be removed to have a better restriction at cardia with the sleeve.

Conversion to sleeve should not be an option for dumping & weight regain which are due to sweet eating. For these patients, a metabolic surgery rather than a restrictive operation, according to BMI should be selected.

We prefer to perform the gastro-gastric anastomosis by hand sewing. Stapler anastomosis might have the risk of stricture.

If the surgeon has less experience, than we recommend to leave the transected jejunal tip as it is and not to do further distal transection and anastomosisi to construct normal intestinal anatomy. This might increase the complication rate, and should be postponed to be fixed in a second session.


  1. Laparoscopic Conversion to Duodenal Switch

The most effective weight loss can only be acchieved with a conversion to Duodenal Switch. This technique needs high qualified surgical skills and expertise.

The main issue in performing a Duodenal Switch to a gastric bypass patient, is the vascular supply of the gastric remnant. As the stomach is transected in to two parts in gastric bypass, the vascularisation of pouch and remnant are seperated for ever. Even when we re-anastomose the two parts of the stomach in revision surgery, they still have different blood supplies. Surgeon should be so gentle and precise when dissecting the post-pyloric duodenum to not to comprimise the integrity of right gastric artery. Other wise the result will definitely be remnant ischemia and resection.

Major Indications for Conversion to Duodenal Switch:

  1. Super obesity
  2. Sweet Eating
  3. Morbid Obesity with Comorbidities


What does the Duodenal Switch brings:

  1. No closed stomach that can not be endoscopically visualised.
  2. Pylorus muscle becomes active.
  3. A larger stomach capacity to have a normal portion.
  4. No Spesific Diet for Life Time.
  5. Best weight loss that can be achieved.
  6. Longest duration of weight loss with FULL FREE DİET.
  8. Laparoscopic Conversion to Transit Bipartisyon

Transit Bipartition, is a new metabolic surgery technique defined by Brazilian surgeon Dr. Santoro. Its designed to treat diabetes in low BMI patients and Dr. Santoro reports no malabsorption after his cases. Its seems to be so because non of the intestinal parts are bypassed in Transit Bipartition. Only a second gastric outlet is formed to ileum part of the bowels. This allows some of the food to pass to distal ileum without digestion and stimulate satiety hormones.

The technique is successful in achieving weight loss and control in diabetes.

However our experience showed that, the new anastomosis can be the dominant path for food by time causing a severe malabsorption. This may not be present at the begining but as the anastomosis enlarge by time, malabsorption may start.

We had to revişe those patients and this was done by a new modification that had been defined by us: The Gastroileal Interposition.

Transit Bipartition (with its malabsorptive capacity) is a good option for weight regain in RYGB or MGB.


Advantages of Transit Bipartion to RYGB:

  1. There is no closed stomach as in RYGB. There is only one stomach and can fully be diagnosed with endoscopy.
  2. The duodenum is preserved and can be endoscopically visualised.
  3. A greater eating capacity with a larger stomach volume.
  4. Significantly better stimulation of distal gut hormones with the new connection.
  5. Patient based adjusted malabsorption that is needed after gastric bypass. This is proprotioned to total bowel length.


We do not recommend Transit Bipartition if the patient had biliary reflux prior to gastric bypass. In these patients, a diversion in pylorus should be done. There are tree options according to BMI for those patients:

  1. Duodenoileal Interposition (Patients BMI < 40 kg/m2)
  2. Duodenojejunal Bypass (Patients BMI 40-50 kg/m2)
  3. Duodenal Switch (Patients BMI > 50 kg/m2)


  1. Laparoscopic Conversion to Duodenoileal Interposition

Ileal Interposition is the first metabolic surgery that had been designed to treat diabetic patients with BMI less then 35 kg/m2. The Pioneer of the technique is Prof. Dr. Aurelio Ludovico De Paula  from Brazil. Dr. De Paula defined two versions of the technique:

  1. Duodenoileal Interposition with Diverted Sleeve Gastrectomy (DII-DSG)
  2. Jejunoileal Interposition with Sleeve Gastrectomy (JII-SG)


The Jejunoileal Interposistion is mainly prefered for obese diabetics that have good beta cell reserves. The main advantage is no duodenal compramisation and no malabsorption.

DII-DSG form is the potent form and is totally modified from Duodenal Switch. DII-DSG can easily be defined as a “non-malabsorptive duodenal switch” surgery. The same distal ileum is anastomosed to post pyloric duodenum as in Duodenal Swith. However, Duodenal Switch directs the food from stomach to large intestines trough a 250 cm distal ileum, but DII-DSG directs the nutrients to 50 cm from the begining of jejunum. This modification allows almost all of the intestines to be in charge of nutrient absorption just like RYGB. The prompt and strong stimulation of distal gut hormones are the main mechanism of action of DII-DSG.


Advantages of Duodenoileal Interposition over RYGB

  1. There is no closed stomach as in RYGB. There is only one stomach and can fully be diagnosed with endoscopy.
  2. The duodenum is anatomically transected. Strong FOREGUT SUPRESSİON as in RYGB.
  3. A greater eating capacity with a larger stomach volume.
  4. Significantly better stimulation of distal gut hormones with the new connection. Strong HINDGUT STIMULATION!
  6. Prefered as a revision option for non-super obese patients.
  7. Best option for patients with Alkaline Reflux with BMI < 40 kg/m2.


  1. Laparoscopic Conversion to Gastroileal Interposition

Gastroileal Interposition with Bipartition is defined as a salvage procedure for low BMI Transit Bipartition patients who have malabsorption. It  was first defined by Dr. Tuğrul Demirel from Turkey. Its a combination of Duodenoileal Interposition and Transit Bipartition that eliminates the long term risks of both procedures.


Advantages of Gastroileal Interposition

  1. There is no closed stomach as in RYGB. There is only one stomach and can fully be diagnosed with endoscopy.
  2. The duodenum is preserved and can be endoscopically visualised. Duodenoileal Interposition and RYGB prevents duodenal endoscopy, ERCP.
  3. A greater eating capacity with a larger stomach volume.
  4. Significantly better stimulation of distal gut hormones with the new connection.
  5. NO MALABSORPTION. The nutrients going trough the new path are directed to the begining of jejunum for full absorption.
  6. No need to adjust the anastomosis. Large anastomosis ensures to receive the whole nutrients to functionally bypass duodenum – FOREGUT SUPRESSION.
  7. Large anastomosis receiving almost all gastric content – HINDGUT STIMULATION; does not form any risk of malabsorption due to diversion to proximal jejunum.

Further Scientific Reading:

Peterli R, Wölnerhanssen BK, Vetter D, Nett P, Gass M, Borbély Y, Peters T, Schiesser M, Schultes B, Beglinger C, Drewe J, Bueter M.

Laparoscopic Sleeve Gastrectomy Versus Roux-Y-Gastric Bypass for Morbid Obesity-3-Year Outcomes of the Prospective Randomized Swiss Multicenter Bypass Or Sleeve Study (SM-BOSS).

Ann Surg. 2017 Mar;265(3):466-473. doi: 10.1097/SLA.0000000000001929.


Amor IB, Debs T, Petrucciani N, Martini F, Kassir R, Gugenheim J.

A Simple Technique of Gastric Pouch Resizing for Inadequate Weight Loss After Roux-en-Y Gastric Bypass.

Obes Surg. 2017 Jan;27(1):273-274. doi: 10.1007/s11695-016-2424-5.


Zorron R, Galvão-Neto MP, Campos J, Branco AJ, Sampaio J, Junghans T, Bothe C, Benzing C, Krenzien F.

From Complex Evolving To Simple: Current Revisional And Endoscopic Procedures Following Bariatric Surgery.

Arq Bras Cir Dig. 2016;29Suppl 1(Suppl 1):128-133. doi: 10.1590/0102-6720201600S10031. English, Portuguese.


Switzer NJ, Karmali S, Gill RS, Sherman V.

Revisional Bariatric Surgery.

Surg Clin North Am. 2016 Aug;96(4):827-42. doi: 10.1016/j.suc.2016.03.004. Review.


Surve A, Zaveri H, Cottam D, Belnap L, Medlin W, Cottam A.

Mid-term outcomes of gastric bypass weight loss failure to duodenal switch.

Surg Obes Relat Dis. 2016 Nov;12(9):1663-1670. doi: 10.1016/j.soard.2016.03.021.

PMID: 27396548


Topart P, Becouarn G.

One-stage conversion of Roux-en-Y gastric bypass to a modified biliopancreatic diversion with duodenal switch using a hybrid sleeve concept.

Surg Obes Relat Dis. 2016 Nov;12(9):1671-1678. doi: 10.1016/j.soard.2016.02.015.