In recent years, more people have chosen surgeries like gastric bypass or bariatric surgery for weight loss and control. According to the American Society of Bariatric Surgery, in the late 1990s approximately 16,000 individuals underwent such surgeries. In 2003, more than 103,000 patients had some form of bariatric surgery. Surgical weight reductions, which are considered major operations, have inherent risks and long-term implications. Because of this, divers should know how these procedures relate to diving.
The Roux-en-Y Gastric Bypass Procedure: The first procedure functions through “malabsorption,” actually bypassing a significant length of small intestine and shortening the overall digestive tract. (Note: most digestion takes place in the intestines and not the stomach.) Shortening the intestines reduces the amount of calories, sugars and fat that would normally be absorbed. This procedure allows patients to eat more normal-sized meals and enjoy a greater variety of foods. Because less food is absorbed, the patient loses weight.
However, some important nutrients, vitamins and other essentials may not be absorbed either, particularly protein, fat, fat-soluble vitamins (vitamins A, D, E and K), iron, calcium and vitamin B12.
Patients can prevent deficiencies by taking appropriate supplements. This surgery produces an aftereffect, a condition known as the “dumping syndrome.” The stomach and intestines move food along by a series of wave-like contractions known as peristalsis. Dumping syndrome occurs when stomach contents are rapidly emptied into the jejunum, which is a part of the small intestine between the duodenum and the ileum. Resulting symptoms include rapid heart rate, profuse sweating, decreased attention span, abdominal pain / cramping, dizziness, diarrhea and flushing.
These can occur from 30 minutes to three hours after one eats. When someone underwater suffers these symptoms, the consequences can be dangerous. Doctors recommend that any patient prone to “dumping syndrome” not dive sooner than three hours after eating.
A variation of the malabsorption procedure is the “duodenal switch,” in which a portion of the bypassed small intestine reconnects to the digestive tract at a different location. This still produces the same malabsorption type results. While it eliminates the dumping syndrome, it requires the same nutritional supplements and medical monitoring.
Adjustable Banded Gastroplasty or "Lap Band" isanother more restrictive procedure which reduces the size of the stomach. Following the surgery, the patient’s stomach may only hold 1-2 tablespoons in volume. This method drastically reduces the amount of food the patient can consume at any one time; digestion continues normally; and nutritional problems such as anemia and osteoporosisare almost nonexistent. The patient does not require as much ongoing medical supervision or dietary supplements.
Patients choosing this procedure must be very selective about the food they eat: since absorption is not altered, any foods high in calories, sugars and fat will have the same affect on the body as they did before the surgery. If a patient consumes too much food or large pieces of food, vomiting can result.
After surgery, some patients experience chronic acid reflux. Reflux and regurgitation of fluid and gastric liquid can present problems for a diver in the “head down” position, such as during descent. Divers can manage problems of regurgitation or vomiting through proper dietary considerations and possibly medications.
Gastrointestinal barotrauma presents more dive-specific issues. During ascent, gas pockets within the gastrointestinal tract expand. If the gas is trapped due to obstructed bowel, rupture could occur. Dive physicians say divers who have had uncomplicated bariatric surgery should not be at any increased risk for gastrointestinal barotrauma.
So, how soon after having bariatric surgery can you dive? Physicians recommend a four to six-week wait after major surgery before you resume strenuous activity. After bariatric surgery, it is probably best to wait longer, until you’ve made some appropriate eating adjustments, dealt with problems such as reflux and vomiting, and you’ve achieved your maximum weight loss. Usually this happens more than a year after surgery.
Divers should not resume diving until they can exercise safely. During any period of convalescence and inactivity, you can lose a significant amount of muscle mass and strength. You should base your A safe return to diving on requires recovery from any therapy and a tolerance for all physical activity that exceeds the reasonable demands of diving - including the exceptional effort that may be required when things do not go quite as planned. and a resumption of exercise that builds the appropriate response to the cardiac and pulmonary exertion you need to dive.
Because obesity is commonly associated with atherosclerosis, diabetes and hypertension, prospective divers who are obese or who have had bariatric surgery should be tested for these conditions and undergo specific exercise testing.