Feeling unwell. lower abdominal discomfort, nausea, slight chills, stomach making unusual noises, loss of appetite, increase in passing gas

Gastroenteritis: This could be food poisoning or a "stomach flu" such as viral gastroenteritis. Get rest, stay hydrated, and eat a bland diet. This should pass in a few days. Should you develop fevers, severe diarrhea or blood in the stool, severe vomiting, inability to tolerate oral intake and feeling dehydrated (dry mouth, dizzy, lightheaded), then I would advise going to the emergency department immediately.