My 50-year-old mother is experiencing an overactive gastro-colic reflex and rapid intestinal transit, causing an urgent need to pass loose, unformed stools almost immediately after consuming meals with medium spices, heavy oils, or outside food. She experiences a feeling of nutrient malabsorption and general weakness during these episodes, but her bowel habits normalize completely into well-formed stools whenever she rests and adheres strictly to a home-cooked bland diet. She currently does not exhibit any major red-flag symptoms such as a high-grade fever, severe localized abdominal pain, visible blood in the stool, but she definitely had some sudden weight loss and her cheeks look so flat and in pain it seems. What is the problem and how to rule out Irritable Bowel Syndrome (IBS-D) or food intolerances.