After increasing water intake and replacing electrolytes, it should relieve most all symptoms of Keto Flu. For an average person that is starting a ketogenic diet, eating 20-30g of net carbs a day, the entire adaptation process will take about 4-5 days. My advice is to cut your carbs to fewer than 15g to ensure that you are well on your way into ketosis within one week. If you are experiencing any more keto flu symptoms, double check your electrolyte intake and adjust.
Next, the surgeon cuts your small intestine and attaches the lower part of it directly to the small stomach pouch. Food then bypasses most of the stomach and the upper part of your small intestine so your body absorbs fewer calories. The surgeon connects the bypassed section farther down to the lower part of the small intestine. This bypassed section is still attached to the main part of your stomach, so digestive juices can move from your stomach and the first part of your small intestine into the lower part of your small intestine. The bypass also changes gut hormones, gut bacteria, and other factors that may affect appetite and metabolism. Gastric bypass is difficult to reverse, although a surgeon may do it if medically necessary.
Onakpoya, I., Posadzki, P., & Ernst, E. (2014, February 17). The efficacy of glucomannan supplementation in overweight and obesity: A systematic review and meta-analysis of randomized clinical trials. [Abstract]. Journal of the American College of Nutrition, 33(1), 70–78. Retrieved from http://www.tandfonline.com/doi/abs/10.1080/07315724.2014.870013