Hi. Thanks for your query. Noted your history of having loose stools for a long time, years together but never really bothered you. You drink a lot of water and feel fine. But you noticed that there was a smell of motor oil. Wants to know whether there can be a factor causing this. The most probable cause can be the overgrowth of bacterial in the intestines, particularly the colon that produce gas that itself smell like a motor oil or when mixed with the smell of stool and/or the gas produced by other bacteria. I would advise you the following: Send your stool for tests for 3 consecutive days. Colonoscopy. Blood for diabetes and the routine. These tests may help to get the cause. Take a course of an antibiotic, metronidazole. Take probiotics and multivitamins, activated charcoal tablets. Reduce sugar intake, take banana and yogurt/curds. This will help us to find the causes of loose stool you have for years together and also help to solve the present problem of stool smelling like a motor oil.