Laparoscopic Mini-gastric bypass (LMGB)

The Mini-gastric bypass (MGB) or One anastomosis gastric bypass (OAGB) is another variation of the gastric bypass. There are two major differences between the MGB/OAGB and RYGB.

The gastric pouch in the MGB/OAGB is longer.

More importantly there is one connection between the gastric pouch and the small intestine.

The MGB/OAGB may have the advantage over the RYGB in being simpler and quicker as an operation. Weight loss seems to be equal among the two procedures with a tendency to have more diarrhea and mal-absorption with the MGB/OAGB.

One of the side effects of MGB/OAGB is bile reflux or the exposure of the gastric pouch to the irritating juices of the bile and pancreas, which in the long-term might lead to pain and ulcers in stomach pouch and intestines. Patients should not be misled by the term “mini”: the MGB/OAGB is not too different from the RYGB as far as risks and side effects and the term “mini” maybe a misnomer.


Long-term results with the MGB/OAGB are similar to the RYGB with total weight loss of 25-30% and improvement or resolution of the majority of obesity related co-morbidities.

Risks and Side Effects

Immediate serious risks following MGB/OAGB occur in less than 3% of patients and include the risk of deep vein thrombosis (blood clots), pulmonary embolus, leak and deep abdominal infection, bleeding and intestinal blockage. Most will appear within the first few days. Some of these complications are best managed with early re-operation. The risk of death is less than 0.1% in experienced bariatric surgical centers such as ours.

Long term side effects include stomach ulcers, gastritis, bile reflux, temporary hair loss, occasional fatigue, anemia, vitamin deficiency, gallstones and loose skin. That is why it is important to maintain regular follow-up and perform blood tests at least twice a year.

Diarrhea and passing gas is a common occurrence after the MGB/OAGB.

Life after the Lap MGB

The average operation takes about 60 minutes and the average stay in the hospital is around 2 days. The phases of diet include clear fluids for three days, thick fluids for five days and soft food for one week. Thereafter food intake becomes normal. Most patients return to work within 10 days of the operation and resume exercise three weeks later.

Long-term commitment to healthy eating habits and regular activity are important to guarantee the success of the operation.

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