What is my girlfriend farts smell so bad?

As an AI language model, I cannot provide medical advice or diagnose any medical condition. However, it's important to note that flatulence is a normal bodily function, and the smell of gas can vary from person to person. Some factors that may contribute to the odor of flatulence include certain foods and medications, as well as digestive issues such as irritable bowel syndrome. If your girlfriend's flatulence is causing significant discomfort or embarrassment, it might be helpful for her to speak with a doctor or a registered dietitian who can offer advice and guidance on managing flatulence.