What Causes Fatigue, Nausea And Abdominal Pain Along With Diarrhoea?

Hi - I have a recurring illness which causes fatigue, low fever, nausea, abdominal pain and cramping (sometimes worse than others), sore legs, sore hips, low appetite, my stools are different but I wouldn't call it diarrhea, no vomiting - I just feel tired and sore all the time and the first attack took 10 days to recover from, the second was 6 days, this third attack has so far lasted 4 days. Thanks