Nausea after eating 10 years after gastric bypass. Is this common this far out from surgery?

Your case could correspond to candy cane syndrome, which is characterized by abdominal pain after eating food, nausea, pain in the left shoulder, and the treatment is surgical with very good results.

Severe nausea 10 years after gastric bypass isn’t typical, but it can happen for several reasons. Since it has been going on for 3-4 months and has led to significant unintended weight loss, it’s important to get it checked out as soon as possible. Possible causes include a stricture or stenosis, which is a narrowing at the connection between your stomach pouch and small intestine that can make it difficult for food to pass. Gastroparesis, or delayed stomach emptying, can also develop over time and lead to nausea after eating.
Bile reflux, which is different from acid reflux, can cause nausea and discomfort after meals and is common in some post-bypass patients. Ulcers or gastritis, particularly at the anastomosis site or in the pouch, could be contributing to your symptoms. If your nausea is accompanied by weakness, sweating, dizziness, or palpitations, reactive hypoglycemia or late dumping syndrome might be the issue. Long-term nutrient deficiencies, especially thiamine (B1), vitamin B12, or iron, can also cause nausea and neurological symptoms.
Since you have lost an additional 30-40 pounds and are struggling to eat, you should see a bariatric surgeon or gastroenterologist as soon as possible. You may need an endoscopy, upper GI study, or CT scan to determine the cause. Until then, try focusing on small meals and softer foods to see if they are easier to tolerate.

You should investigate the cause of nausea, it may be simple gastritis that requires medical treatment or gallbladder stones that needs surgical intervention. You should do ultrasound to exclude the gallbladder stones. Hope that helps