Possible causes of maldigestion are bad food choices, anxiety, stress, enzyme deficiency, and many others. Junk food, for instance, irritates the digestive organs and reduces digestive speed and efficiency. Research indicates that today most people have weak digestion and poor intestinal flora. Maldigestion can cause belching, flatulence, bloating, heartburn, as well as serious nutritional deficiencies leading to weight gain and all kinds of digestive disorders. These, in turn, may cause allergies, aches and pains, fatigue, skin problems, moodiness, etc.