Why am I severely bloated 3 years post gastric bypass?

you probably have protein deficiency, the ideal is to carry out studies to assess your nutritional status

Severe bloating and stomach pain after eating, especially worsening years after gastric bypass, could have several possible causes. One of the most common is Small Intestinal Bacterial Overgrowth (SIBO), which occurs when bacteria overgrow in the small intestine due to changes in digestion after bypass. This can lead to extreme bloating, gas, and discomfort. Another possibility is an atypical form of dumping syndrome, where the body reacts to certain foods by causing bloating and pain rather than the usual dizziness or heart palpitations.
Gastroparesis, or delayed stomach emptying, could also be a factor. Although more common with gastric sleeve, it can still happen after a bypass and result in food sitting too long in the stomach, causing bloating and discomfort. Another concern is a partial intestinal obstruction or stricture due to scar tissue from the surgery, which could slow food movement and cause severe bloating and pain.
Bile acid malabsorption might be contributing to the symptoms, as gastric bypass alters how bile is processed, sometimes leading to excessive bile in the intestines, resulting in bloating and diarrhea. Food intolerances, particularly to dairy, sugar alcohols, or high-fiber foods, could also be triggering these symptoms.
One of the most serious possibilities is an internal hernia, such as Petersen’s hernia, which happens when the intestines twist inside the abdomen. This can cause intermittent or worsening pain and bloating and, if left untreated, may become a medical emergency. Since your symptoms are getting worse over time, it would be best to see your bariatric surgeon or a gastroenterologist as soon as possible. If you experience severe pain, vomiting, or an inability to pass gas or stool, going to the ER immediately is crucial.