Revisional bariatric endoscopy procedures done for weight regain or pain related to ulcer and gastro-gastric fistulae are primarily done in patients who have undergone Roux-en-Y gastric bypass (RYGB). This is the bariatric endoscopic patient population in which the nutritional management is most challenging and, hence, will be the focus of the discussions below.

RYGB is generally done laparoscopically but may also be done through the original “open” approach. A 2 oz capacity gastric pouch is created from the upper portion of the stomach based on the lesser curve of the stomach and directly below the esophageal sphincter. The jejunum is divided 40–50 cm distal to the ligament of Treitz, and the distal jejunal “roux” limb is brought up to and anastomosed to the gastric pouch. A jejunojejunostomy is then performed to reestablish biliopancreatic continuity with the intestinal tract.

The final configuration results in a small gastric pouch which severely restricts caloric intake and three “limbs” of small intestine (Fig. 14.1). First, there is an “alimentary” limb which carries food and liquid from the gastric pouch to the jejunojejunal anastomosis. This limb typically measures approximately 125 cm. This limb is not in continuity with the biliopancreatic secretions. In addition, food and liquid in the alimentary limb bypass the majority of the stomach, all of the duodenum, and the first part of the jejunum because of the altered anatomy. As a consequence, those nutrients that need these secretions or intestinal components for digestion have decreased absorption in the post-RYGB patient (Fig. 14.2). A “biliopancreatic” limb carries bile and exocrine pancreatic secretions from the liver and pancreas, respectively, to the jejunojejunostomy. Finally, there is a “common” limb which starts at the confluence of the alimentary and biliopancreatic limbs and travels distally to the ileocecal valve. Prior to endoscopic intervention, postoperative RYGB patients who have enlarged gastric pouch and/or anastomosis or have developed gastro-gastric fistula may be able to easily eat any and all foodstuffs, which is largely responsible for their weight gain. After endoscopic intervention, restriction of food intake is similar to that experienced after original gastric bypass procedures. The goals of dietary management post-procedure are to provide sufficient fluid and protein. This requires reintroducing food and consistencies slowly to assess food intolerances. Most RYGB patients are able to advance from clear liquids to full liquids, to ground foods, and finally to a low-fat controlled portion meal plan in about 4–6 weeks. Transitioning from one stage to the next should be individualized based on the patient’s ability to meet fluid and protein goals at their current stage.

Patients are frequently challenged during the diet progression due to many factors. Each patient presents with a history of eating behaviors and patterns, environmental and behavioral triggers, food preferences, and food dislikes. Immediately post-procedure each patient has to eliminate lifelong habits and modify their food and liquid preferences. Particular challenges can come from the fact that previously preferred foods may no longer be tolerated. Ongoing exposure to food triggers in the form of advertisements, social situations, behavioral patterns, and food cravings can be overwhelming and should be anticipated. There may also be a “honeymoon phase” during which the patient has decreased or no hunger. The duration of this phase varies, but it does ­inevitably end, at which point patients report that their physical hunger returns. Helping the patient navigate these experiences will improve ­short-term success and decrease the likelihood of the all too common peri-procedure complications of nausea, vomiting, dehydration, and abdominal pain.

Endoscopic procedures are frequently done on an outpatient basis. Hence, the patients should be scheduled for a follow-up visit with the RD shortly after their procedures to reinforce the postoperative diet progression. Initially, patients are limited to sipping fluids and consuming extremely small bites of food resulting in restricted caloric intake. The RD will emphasize the importance of consuming small, frequent liquids and meals; eating until satiated and not beyond; and keeping a food record once food intake begins. The patients’ diets are slowly advanced over time through “stages,” which allows them to get reacquainted with dietary restrictions and allows the endoscopic site to heal. A low-fat, solid food diet is achieved 4–6 weeks after intervention. This transition is greatly improved with pre-procedure dietary education.

Given both the highly restrictive nature of the RYGB and malabsorption component, these patients are at high risk for vitamin and mineral deficiencies. One can easily predict the common deficiencies seen following gastric bypass by understanding the postsurgical anatomy and where vitamin and minerals are usually absorbed in people with an altered anatomy (Fig. 14.2). Postoperatively patients are most commonly at risk for developing iron, calcium, vitamin D, and vitamin B12 deficiencies [3, 4]. Patients that have complications after surgery such as excessive weight loss, nausea/vomiting, or poor compliance to diet can have an increased risk of becoming deficient in the above-mentioned vitamins as well as thiamine and folate. Other rare deficiencies include copper which should be thought of particularly in the bariatric surgical patient with neurological deficits [4, 5].

Postsurgery patients are encouraged to take at least two chewable multivitamins as well as two calcium plus vitamin D supplements to help avoid such deficiencies. Some advise prophylactic administration of vitamin B12, folate, iron, and additional B vitamins. Chewable supplements are advised for at least the first 3 months given these are better tolerated given the limited pouch size and the potential for better absorption. Vitamin and mineral levels should be checked on a regular basis in these patients as they often need repletion, and long-term deficiency can contribute to anemia and neurological deficits. One strategy for long-term micronutrient screening is presented in Table 14.1. Other strategies are also appropriate, and the actual protocol used depends on the bariatric program to which a patient belongs. The important factors are that screening is regular and lifelong. It should be noted that once a nutrient deficiency has been identified, more frequent monitoring and assessment are required until the deficiency is repleted and stabilized. Vitamin and mineral supplementation is described in more detail below.

The appropriate diet after gastric bypass not only takes into account the restrictive nature of the gastric pouch, but also the bypass of the pylorus, duodenum, and first part of the jejunum. The pylorus normally regulates the movement of food from the stomach to the duodenum. However, following gastric bypass, food flows from the small gastric pouch directly into the jejunum. As a consequence, concentrated sugars and high-fat foods are not well tolerated and can lead to dumping syndrome. This includes foods and liquids with added sugars or high in concentrated sugars such as fruit juices, sugary baked goods (e.g., cupcakes with icing), ice cream, and many fried foods. The syndrome can be classified as either “early” or “late” dumping.

Early dumping occurs during or 10–30 min after a meal. Hyperosmolar foods enter the jejunum rapidly causing fluid shifts from the intravascular compartment to intestinal lumen. This leads to nausea, diarrhea, palpitations, and abdominal cramping. This is the most common type of dumping. However, a patient can experience late dumping or reactive hypoglycemia as well. This occurs 1–3 h after eating and is mainly characterized by vascular symptoms like flushing, dizziness, palpitations, and light-headedness. This is thought to be due to increased release of insulin causing hypoglycemia [6, 7].

Dumping syndrome can be quite debilitating and noxious to patients. Thus, the dietary stages after RYGB emphasize noncaloric, sugar-free liquids and lean, high-protein foods and fluids to avoid this syndrome. If a patient avoids food with added sugar, concentrated sweet foods, and high-fat foods, he/she will be unlikely to develop dumping syndrome. As patients get farther out from surgery, the severity of dumping syndrome usually decreases, and some patients are not susceptible to dumping syndrome.

Long-term weight maintenance following the initial RYGB and endoscopic revision of RYGB depends heavily on food-related behaviors. Physical hunger may be managed initially and almost solely by the surgery or endoscopy, at least for a time. However, the ability to control maladaptive eating in the long run, and thus weight regain, requires ongoing effort primarily from the patient himself. Weight loss efficacy is limited, and regain of weight is potentiated in patients who “graze” on dry, crisp foods (e.g., potato chips, crackers), liquid calories (e.g., juice, creamy soups), or sweetened foods (e.g., ice cream), if tolerated. The ability and willingness to eat such foods throughout the day, though in small quantities, will eventually defeat the RYGB even if the post-procedure anatomy is anatomically perfect. Such patients are doomed to poor weight loss. Because patients are at lifelong risk from developing such maladaptive behavior, it is imperative that there be lifelong follow-up with the nutrition specialist as well as surgeon/endoscopist to improve and ensure long-term weight loss efficacy.

It should be noted that one of the most common reasons—if not the most common reason—for admission to the hospital after a bariatric procedure is dehydration. Dehydration leads to nausea and vomiting. Nausea and vomiting lead to further dehydration. This results in an endless cycle, which the patient cannot resolve because their small gastric pouches limit their abilities to drink sufficient water to reverse the dehydration. To prevent this, patients need to consume 64 or more ounces of fluid daily. The fluid should be consumed slowly throughout the course of the day given the small gastric pouch and the inability to drink large quantities of water at one sitting. They also need to avoid dietary indiscretions or habits that will cause vomiting like eating or drinking too quickly. Actual fluid requirements vary by patients to avoid dehydration. Patients will also be ingesting fluids from food, but with a decrease in food volume, patients may require increased fluid intake.

On average, RYGB patients lose 60–70% of their excess body weights over the first 1–2 years after surgery. Thus, they have dramatic changes in fat, lean body mass, and vitamin and mineral stores. Following endoscopic revision, one can ideally anticipate return to such levels of weight loss efficacy. Maximizing preoperative education and identifying addictive behaviors, specific food urges, and other issues including depression can help to ensure post-procedure weight loss [2]. Ongoing follow-up with the RD, surgeon, and endoscopist is needed to ensure successful weight loss as well as monitoring for nutritional complications due to excessive nausea, vomiting, and intolerance to foods. As discussed below, there are several considerations for management of these patients on a lifelong basis.