Bariatric surgery, such as gastric bypass or sleeve gastrectomy, can be life-changing for a person struggling with obesity. Not only can weight loss be significant, these procedures help improve several chronic conditions, including type 2 diabetes and heart disease. That said, unintended consequences sometimes arise after surgery.

"There are multiple types of weight-loss surgery, and each has a few complications or issues that can occur and require further treatment," says Dr. Garth Davis, a bariatric surgeon at Houston Methodist. "It's not particularly common to need surgery again, but it happens."

Estimates suggest less than 15% of weight-loss surgeries require follow-up surgery, which is called bariatric revision surgery.

When is bariatric revision surgery needed?

Revision of a previous weight-loss surgery may be recommended if one of the following issues arises:

• Insufficient weight loss
• Weight regain
• Severe acid reflux
• Complications, such as hernias, ulcerations or stomach erosion

The different types of weight-loss surgery are prone to certain issues more than others.

For instance, changes in anatomy — such as the pouch or sleeve stretching — can sometimes occur after gastric bypass or sleeve gastrectomy. This reduces the effectiveness of the surgery and can lead to insufficient weight loss or weight regain. Such stretching is more common after sleeve gastrectomy than gastric bypass, Dr. Davis notes.

"Severe acid reflux after sleeve gastrectomy is the most common reason to need bariatric surgery revision these days," says Dr. Davis. "Complications after gastric band surgery — erosion or slippage of the band — used to be much more common, but the procedure isn't performed anymore, so we see these issues less frequently now."

What are the signs revision surgery may be needed?

Consult a bariatric surgeon if one of the following signs and symptoms arise after weight-loss surgery:

• Abdominal pain
• Vomiting
• Frequent nausea
• Chronic acid reflux
• Extreme hunger

"Just because you notice one of these issues doesn't mean you need another surgery, but it's important for the problem to be thoroughly assessed by a surgeon," explains Dr. Davis. "If you're hungry all the time, it might be that you're not eating the right foods. Your bariatric surgeon can help recommend the diet and lifestyle changes that make your procedure most effective."

But Dr. Davis notes that increased appetite could also be the result of a poorly performed procedure or a dilated sleeve — either of which require surgery to correct.

"Another thing I commonly see is a patient who had sleeve gastrectomy but is now regaining weight and thinking there is nothing else that can be done," adds Dr. Davis. "And that's not true."

If you have questions about your weight-loss progress or concerning symptoms, it's important to specifically see a bariatric surgeon. Their expertise is often what's needed to help correctly define the problem, a critical step in knowing whether revision surgery may be needed. Another example is if you're struggling with acid reflux.

"This really shouldn't be managed by other doctors," says Dr. Davis. "Instead of taking a bunch of medications and never really seeing any symptom improvement, a bariatric surgeon will know that there's a surgery to fix severe acid reflux after sleeve gastrectomy."

How does revision weight-loss surgery work?

How revision surgery is performed depends on both the initial procedure and the issue or complication that's arisen. In some cases, the initial procedure can be modified or repaired, whereas other cases may require conversion to a different weight-loss technique. Your doctor will evaluate your situation and explain which surgical intervention is right for you.

"If a patient regains weight after sleeve gastrectomy, we typically convert to a gastric bypass instead of trying to correct dilation of a sleeve, for instance," says Dr. Davis. "We see better long-term weight loss with gastric bypass."

The same goes for a person who's experiencing severe acid reflux after sleeve gastrectomy, since gastric bypass can help treat that issue as well.

Problems related to a complication with a gastric bypass — ulcerations or pouch stretching — can typically be corrected without converting to a different procedure.

A gastric band that's eroding or leading to a blockage is typically corrected by removal of the band and conversion to a gastric bypass.

"The steps to undergo revision surgery are similar to that of the first procedure," adds Dr. Davis. "We first make sure that lifestyle issues are addressed, which requires meeting with a behavioral therapist and dietitian."

Surgery recovery and follow-up care are similar, too. Just as with your first procedure, your care team will help you understand what to expect and what steps are needed to help achieve long-term weight loss.