The Roux-en-Y Gastric Bypass – often called gastric bypass – is considered the ‘gold standard’ of weight loss surgery and is the second most commonly performed bariatric procedure worldwide. Gastric bypass involves both restrictive and malabsorptive components to produce long-term weight loss. It is restrictive as a result of the creation of a small stomach pouch, and malabsorptive because it creates a method for bypassing a variable portion of the small intestine depending on a patient's BMI before surgery. 

The Procedure

There are two components to the gastric bypass procedure. First, a small stomach pouch, approximately one ounce or 30 milliliters in volume, is created by dividing the top of the stomach from the rest of the stomach. Next, a Y-shaped section of the small intestine is attached to the pouch allowing food to bypass the main stomach. Bypassing the two segments of the small intestine, known as the duodenum and part of the jejunum, allows the body to reduce the amount of calories and nutrients the body absorbs.

The gastric bypass works because the newly created stomach pouch is considerably smaller and can only hold a few ounces of food at a time, which translates into fewer calories consumed. There is less digestion of food by the smaller stomach pouch, and the segment of small intestine that would normally absorb calories as well as nutrients no longer has food going through it, so there is less absorption of calories and nutrients. Most importantly, the rerouting of the digestive process produces changes in gut hormones that promote satiety, suppress hunger, and reverse one of the primary mechanisms by which obesity induces type 2 diabetes.

Roux-en-Y gastric bypass

Gastric bypass surgery can be performed as a laparoscopic (minimally invasive) procedure which involves the use of a small telescope-like camera inserted through a small incision made in the abdomen, or as an open procedure where a large midline incision is made in the abdomen. The laparoscopic method is the most commonly used by Dr. Averbach and Dr. Hamdallah, but not everyone is a candidate for this type of surgery. You and Drs. Averbach and Hamdallah can decide together which procedure is right for you.


  • Low mortality rate (0.2%)
  • Weight loss of 65 to 70% of pre-operative excess weight within one year
  • Overall improved health
  • Resolution or elimination of co-morbidities such as type II diabetes, sleep apnea, hypertension and some others


  • Disruption of the staple line can lead to leakage or serious infection
  • Possible malnutrition or anemia
  • Possible obstruction of the GI tract
  • Risk of marginal ulcer
  • Risk of dumping syndrome
  • Requires adherence to dietary recommendations, life-long vitamin/mineral supplementation, and follow-up compliance



Make an Appointment



Appointment Request

In Affiliation With Saint Agnes Healthcare


For more than 150 years, Saint Agnes Hospital has been dedicated to the art of healing by providing exceptional care to the greater Baltimore area. Built on a strong foundation of excellent medical care and compassion, Saint Agnes is committed to providing the best care for our patients for many years to come.