I recently had constipation which is now no longer a problem. However, it is possible it is still there but very minor. While I was still suffering and whilst recovering, I noticed slight enlargement of certain parts of the stomach, to a degree where it was noticeable by me to plain eyesight. It is minor and I would not define it as swelling and it is not inflamed. I have had some stomach pain but this 'enlargement' may not be the cause of it and the pain is nothing major, with no vomiting and could even be psychosomatic. The enlargement is around my left side of the abdomen (actually located at the abdominal muscles near the belly button) and it more noticeable shortly after eating. There is also something similar at the upper right part of the abdomen (again on the muscular area near the belly button). This might have been here before the constipation I do not know, but I only recognised it while I was recovering as I said. I have had stomach problems in the past, some of which caused vomiting and rather bad pain, but it has always subsided.

Does anybody know what the issue could be or whether it is a problem?

Any swelling or enlargement should be investigated. Go let the Doctor look at it, just to illiminate any worries you may be having.