Does Malabsorption of the Roux-en-Y Gastric Bypass Change Over Time?
June 20, 2018The Roux-en-Y Gastric Bypass is a surgical operation that causes weight loss by both limiting the amount of food that a person is able to eat (restrictive) while causing malabsorption of the nutrition and calories consumed. The intestinal Roux limb of the RNY is reattached much lower in the intestinal tract causing less intestinal length for absorption. The question I have been asked by the ObesityHelp.com Community is, "Does malabsorption of the Roux-en-Y Gastric Bypass pouch change over time?" This is a question that we likely will never be able to directly measure but it might. This is why I say it might.
Let's begin with three different patient examples.
Malabsorption with the Gastric Bypass Patient 1
My first patient is “FP” and he is a 55-year-old male who came to my office interested in weight loss surgery because he was morbidly obese. FP and I sat down and began reviewing his health history. This was early in my career and before Gastric Banding surgery or Endoluminal procedures (such as Gastric Balloons) so we were discussing the possibility of FP having the Gastric Bypass operation.
In reviewing FPs history, he shared that he had been in a near-fatal car accident when he was 16 years old. He sustained serious abdominal injuries. He underwent life-saving surgery which required removal of almost all of his small intestine. The accident was so severe and his intestinal loss so profound that following the accident, he was not able to consume and absorb enough calories to sustain life.
FP existed on TPN (nutrition through an IV). FP required TPN for the next five years while slowly transitioning back to a normal diet. His intestine did not grow in length but it did adapt by increasing its ability to absorb. This continued to today where he is now absorbing so many calories that he is morbidly obese. Obviously, he was not a candidate for the Gastric Bypass operation since he has so very little small intestine, but his story of intestinal recovery amazed me.
Malabsorption with the Gastric Bypass Patient 2
My second patient is “SP” and she underwent a Roux-en-Y Gastric Bypass in 2008, only to be readmitted several days following surgery with severe abdominal pain. She was taken back into surgery for an emergent abdominal exploration, which demonstrated almost all of her small intestine had lost blood flow due to an undiagnosed and unknown complication of a blood clotting disorder.
She was seriously ill and was in the Intensive Care Unit for several months. SP underwent several operations in attempts to save her small intestine which were for the most part unsuccessful. There were even discussions about a possible intestinal transplant. All but 100 cm of her intestine had to be ultimately removed.
As with FP, SP's life was sustained by IV nutrition for the next two years. She slowly transitioned back onto a regular diet. In monitoring her nutritional needs, when she started eating regular food, she demonstrated severe malabsorption with the inability to absorb fluids, critical vitamins and or nutrients. Over the next 10 years her small intestine, though limited in length, was able to adapt and increase its ability to absorb. Today she is in an almost normal state of health.
In SP’s case, she is not morbidly obese and actually maintains a healthy weight so there is that difference. Also, she is 10 years out from surgery while FP is 35 years out. Again, I do not know if this makes a difference.
What I do believe is that each of us adapts to challenges differently but because of my own experience with FP and with SP, I believe that intestinal malabsorption for whatever reason can progress and improve over time.
If Malabsorption is Less, What's the Difference for RNY Weight Loss?
In an excellent study, researchers took individuals whose BMI averaged 50 or above and randomized them into one of two groups. The only difference, the first group had a very short intestinal Roux limb (less malabsorption), the second group had a very long intestinal Roux limb (more malabsorption).
The thought was that the patients with the longer intestinal Roux limb and more intestinal malabsorption should lose more weight. What they found to be true is that the percentage of weight loss was exactly the same for each group. The longer limb, with more malabsorption, did not allow for more weight loss. The only difference found was the group with the longer Roux limb and more malabsorption had more nutritional deficiencies.
With this in mind, I personally make very small Sleeve stomachs. The Sleeve stomach has a normal inlet and normal outlet and normal digestion so there is no malabsorption.
If you compare my Sleeve patients' excess weight loss to my Roux-en-Y patients' excess weight loss, here are the numbers.
- My Sleeve patients are typically restricted to a ¾ cup to 1 cup of food, and on average lose 68% excess weight in one year.
- My Roux-en-Y patients are restricted to a ¾ to 1 cup of food, and on average lose 73% excess weight in one year.
One might conclude, the malabsorption aspect of the Gastric Bypass might contribute an extra 5% to the total excess weight lost following Gastric Bypass.
So, with these two comparisons in mind, one might argue that:
- The malabsorption component of the RNY contributes to a smaller percentage of the total amount of weight loss that follows RNY surgery.
and - The amount or degree of malabsorption has little or no effect on total excess weight loss which, in these cases, more is not better.
Malabsorption with the Gastric Bypass Patient 3
That takes me to a final story and my final patient. Several years ago, my wife and I were refinancing our home and we met with our broker to finalize all of our paperwork. As we began signing the multitudes of papers required for this process, we began to chat. She asked me what I did and I told her that I was a bariatric surgeon. She got very excited and stated she had that operation but she has gained all of her weight back. I was surprised. We began talking about what food choices she was making and the quantity of food that she could eat. “Well,” she answered,“last night I ate ¾ of a pizza.” With this, I told her I thought her Bypass must have broken down and asked her to get her medical records and to come in to see me so I could determine how I could help her.
Her records arrived prior to our visit, and I reviewed her operation report, which described a very standard Roux-en-Y operation. I saw her in my clinic and ordered several studies to best evaluate her Gastric Bypass anatomy. I reviewed those test results which defined a perfect, intact Gastric Bypass.
After discussing these normal findings with her, I again asked if “she really could eat ¾ of a pizza”? She said she definitively could. Baffled, I then asked does it hurt? “Oh yes,” she responded. “I get crushing chest pain up to my throat that lasts for hours.” What became apparent was that my broker was able to ¾ of a pizza because she was stacking the pizza in her esophagus up to her throat. This caused her intense pain lasting for hours or about the time it takes for the pizza to move down into normal digestion.
There was nothing that I could do surgically to improve or correct her operation. What needed to change was her relationship to food. I scheduled her to meet with our nurse clinician, our psychologist, and our dietician.
With all this in mind, if you are a patient a few years out following RNY, and are finding yourself regaining weight, a change in your bypass malabsorption would not be my first consideration causing that weight gain. I would recommend, as I do in my practice, to reconnect with the dietician in your program – review your food choices and portion size, and determine together if there is an underlying issue or if you really just need to get back on track with diet choices and exercise. In my experience, nine times out of ten, this is the case.
My answer to the question asked? I do believe that there can be a change in malabsorption following the Roux-en-Y Gastric Bypass with some patients, and this change might allow for more food tolerances. Could these food tolerances cause weight regain? Possibly, but I do not believe that having less malabsorption alone, would be significant enough to be the single cause of substantial weight regain.
Take All of Your Required Vitamins and Supplements Every Day
In closing, I would like to address a very important consideration following the gastric bypass operation and its inherent malabsorption. Because of the malabsorptive with this procedure, it is imperative for a patient, to take all of their required vitamins and supplements every day for the rest of their life. In our program, these vitamins include a complete multivitamin, Calcium, Vitamin D, B12, and possibly iron. Otherwise, you are at risk for vitamin and mineral deficiencies that could lead to long-term health issues.
This is why also an annual assessment of your nutritional fitness is so important. In our program, this analysis includes evaluating your parathyroid activity (intact PTH), vitamin D level, B vitamin support (thiamine, B12, and folate), Hgb, iron stores, protein support (albumin) as well possibly zinc, copper, and/or other fat-soluble vitamin levels if indicated.
Understand these vitamin issues remain for the long-term following surgery because of the malabsorption changes that happen following the bypass operation. Annual labs allow you to be assessed, and your supplementation altered, if needed, to maintain you in optimal health.
Dr. Jeffrey Baker is a board-certified physician specializing in bariatric surgery at Riverside Medical Center.
 | ABOUT THE AUTHOR Dr. Jeffrey Baker is a board-certified physician specializing in bariatric surgery at Riverside Medical Center. He has performed over 2,500 weight loss surgeries since specializing in bariatrics in 2003. He sits on the review boards of two international state-of-the-art medical device companies developing new technologies for bariatric innovations. Read more articles by Dr. Baker! |
