Hello i appreciate your concern long standing diarrhoea for 3 years could be related to Inflammatory bowel disease irritable bowel disease malabsorption syndrome HIV related diarrhoea in my opinion you should visit a gastroenterologist for clinical examination and investigations like colonoscopy or a biopsy and certain blood test like CBC liver function test thyroid function test and an HIV test have plenty of dietary fibers and fresh fruits multivitamin supplements I hope this addresses your question Thanks for your question get well soon