Hi there. There are movements constantly happening inside your abdomen - basically it is the stomach, small intestines and large intestines trying to push the food forward. Now in thin individuals, following a large meal and in cases like irritable bowel syndrome and loose stools like diarrhoea or dysentery etc. Those movements are more easily appreciated. If it is associated with pain and a sense of need to evacuate your bowel which gives you relief then its more likely to be Irritable bowel syndrome which is fairly common and seen in a lot of people. If it is bothering you then i suggest you start by getting a stool routine test done. That ll tell you if you have any infection to begin with.