I been having diarrhea for the past month, what could it be? also have loss of appetite, fatigue, and stomach pains

Diarrhea : It's too prolonged to attribute it to a simple viral intestinal tract infection. Bacterial or parasitic causes are possible and require a fresh,warm stool sample for culture. Irritable bowel syndrome, inflammatory bowel disease, Gluten intolerance or sensitivity are possibilities. I strongly recommend consulting a gastroenterologist for evaluation and treatment. Appropriate testing will be done.