Excessive flatulence, bloating, constipation or diarrhoea, burping, a feeling of heaviness or nausea after meals, lack of appetite for meat or a desire to eat despite having a full stomach, heartburn, reflux, and a sour aftertaste in the mouth are just some of the symptoms of insufficient stomach acid. If you also suffer from allergies, psoriasis, or malabsorption, have observed recurring rashes, are underweight or obese, have brittle nails, hair loss or undigested food in your stool, it most likely means that your stomach is secreting too little stomach acid.