Indigestion. Sometimes indigestion is due a condition known as heart burn. Start with your diet. Watch carbohydrates especially how they are combined with the rest of your food. Sometimes taking antacids will help. Sometimes the symptoms are due to disorders in the GI tract such as gerd, or gall bladder disease. If you are concerned about these, see your doctor.
What are you asking? What are you experiencing that suggests "mal"-digestion is present? You question will be better answered if we can hear from you: 1) your bowel habits (have these changed)?; 2) food intolerances noted; 3) unwanted weight loss/gain?; 4) co-morbidties (are you diabetic, on medications that alter digestion)?; 5) appetite/fullness; 6) bleeding; 7) symptoms that cause you to feel digestion is impaired?