In our patients with sleeve gastrectomy and patients with gastric bypass, if there is a weight gain and this does not change with diet or by rearranging their life habits, then revision surgeries are in question. According to the first surgery, there are several types of revision surgery. If the patient had a sleeve gastrectomy in the first operation, revision surgery can be easily performed. Because we did not use the small intestine there before, now we have a chance to use it. However, if the first operation is gastric bypass, it may be a little more difficult to perform revision surgery since we have already used this option. In summary, we have several alternatives for revision. We can either convert sleeve gastrectomy to mini gastric bypass, or we can convert it to gastric bypass. If the stomach is overly enlarged, we can do this in the form of a re-sleeve or a second sleeve.