Final answer:
Foul, fatty, frothy stools are a symptom of steatorrhoea, which can be associated with diseases like Crohn's disease, cystic fibrosis, and ulcerative colitis, all of which can lead to malabsorption of fats.
Step-by-step explanation:
Foul, fatty, frothy stools are often indicative of a condition known as steatorrhoea, which is the result of malabsorption of fats in the digestive system. This can occur due to a variety of underlying issues, including obstruction to the flow of bile, defects in lipid digestion, or impairment in the absorption of digested lipids. One specific disease associated with these symptoms is Crohn's disease, an inflammatory bowel disease that affects any part of the gastrointestinal tract and can lead to malnutrition due to faulty absorption. Other diseases characterized by fat malabsorption include cystic fibrosis and ulcerative colitis. Conditions like these can result in the excessive loss of fat in stools, which becomes apparent as steatorrhoea.