While many factors can contribute to diarrhea and indigestion, there are some key foods that are best avoided, particularly if you find yourself subject to bouts of either condition. Spicy, fatty or greasy foods typically cause indigestion, while diarrhea can be the result of consuming food additives such as sugar alcohols or fat substitutes as well as foods, such as dairy, that are common triggers of food allergies.
Common Causes of Diarrhea
Diarrhea -- the passing of loose or watery stool -- can make you feel dehydrated and weak, but typically it goes away within a few days. According to MedlinePlus, the most common cause of diarrhea is viral gastroenteritis -- the stomach flu. Other common causes include antibiotics, laxatives containing magnesium, chemotherapy drugs and medical disorders, including celiac disease, inflammatory bowel disease, lactose intolerance and malabsorption syndromes.
Lactose is a sugar in milk that cannot be properly digested by those with lactose intolerance. Symptoms of lactose intolerance include diarrhea, gas, nausea and abdominal pain. Intolerances to other foods can also cause diarrhea. The Centers for Disease Control and Prevention notes that soy protein, fructose, sorbitol and olestra can also cause diarrhea in those with intolerances. Sorbitol and other sugar alcohols, including mannitol, xylitol, lactitol, isomalt, maltitol and hydrogenated starch hydrolysates, are not fully digested by the body, which can lead to diarrhea and bloating in some individuals. Olestra, a fat substitute used in snack foods such as chips, can cause severe diarrhea, according to the Center for Science in the Public Interest.
Common Causes of Indigestion
Indigestion is characterized by an uncomfortable feeling in the abdomen that occurs during or after eating. Indigestion can include feelings of burning and pain but is not the same thing as heartburn, notes MedlinePlus. Some of the most common causes of indigestion include excessive alcohol consumption, smoking, spicy, fatty or greasy foods, high-fiber foods, excessive caffeine intake, stress, overeating or eating too fast. Less common causes can include pancreatitis, gallstones, stomach ulcers or inflammation in the lining of the stomach.
Indigestion is not simply caused by the type of foods consumed but also the circumstances in which they are consumed. It is important to eat when you're in a relaxed state of mind, to eat slowly and to stop eating when you're full. Examples of foods that may cause indigestion include fast foods, fried foods, hot peppers, spicy sauces and acidic foods such as citrus fruit and tomatoes. The Cleveland Clinic also notes that you can avoid indigestion by waiting at least three hours after your last meal before going to bed, sleeping with your head elevated, avoiding tight-fitting clothing and waiting at least an hour after eating to exercise.