After having taken the meal stomach goes bloated, any idea why?

Bloat. Bloating is very common and is usually benign. However, without knowing more about you and your history, impossible to say. The list ranges from lactose intolerance, ulcers to cancers to poor stomach tolerance to food and distension to celiac disease. Red flags would include weight loss, vomiting, black or bloody stools, diarrhea. Either way some basic tests would be helpful. Try a dietary log.