Then it could be owing to:

The medical profession are keen on antacids and proton pump inhibitors but many people have low stomach acid not high.  Stomach acid protects your digestive tract from the outside world (much like the water in your toilet stops germs and smells coming up from the sewers, stomach acid acts as a barrier to bugs and bacteria).  The acid also prepares food for digestion, softening and opening up protein fibres and helping to do the initial breakdown of foods.  Production of stomach acid can begin to reduce after the age of about 30 but some people may have always had low stomach acid and it can run in families.  If the first stage of digestion is impaired owing to lack of acid then it allows food to pass into the intestines in an inappropriate state and can cause bloating and discomfort as the foods begin to ferment (and rot when the food passes too slowly through the digestive tract).  To find out if your stomach acid is low, first thing in the morning before you eat or drink anything take a small glass of water, add a heaped teaspoon of bicarb of soda and drink.  If you are not burping your head of within 5 minutes then it means your stomach acid is low and it would be useful to read the section on indigestion. 

Stomach acid needs vitamin c to activate it.  Without sufficient vitamin c the acid is inactive and will impair your digestion creating the same result as having low stomach acid.  If you diet has little or no vitamin c then you need to add at least three portions of fruit high in vitamin c per day.  And the best time to eat it is half an hour before you intend to have a meal on an empty stomach.  Or have the juice of half a lemon or lime in a pint of warm water half an hour before a meal.  Kiwi fruit, strawberries, blueberries, physalis and citrus fruits are all high in vitamin c. Also do the test in the previous section to check that you have sufficient stomach acid for efficient digestion.

Being dehydrated is a common cause of poor digestion (and IBS type symptoms in general).  The first stage of digestion, called the cephallic stage, starts in your brain.  You know how when you are cooking something that smells delicous such a bacon for carnivores or perhaps garlic for the vegetarians, your mouth starts to water and your stomach gets the message that food is on the way and it gets ready by flooding with gastric juices.  If you are chronically dehydrated (which many people are) your stomach has little or nothing to flood with and so digestion is impaired. You need 35mls of water for every kilo of body weight.  And you need it throughout the day.  Read the section on indigestion for more information on dehydration and it's impact on your health.

Many of the people who come to my clinic feeling worse after they eat do so because they are eating junk food full of additives and very few nutrients.  My definition of junk food may not be the same as yours.  You might think of junk food as being take aways but I think of it as being anything that comes in a box or a packet.  A healthy diet is one that contains whole grains (such a wholegrain bread or pasta, brown rice, at the very least 6 portions of fruit and veg (and ideally 9 - 14), three servings of good quality protein (such as eggs, meat, fish, quinoa, and combinations of foods to make complete proteins such as mushrooms with brown rice for vegetarians) some nuts and seeds and fats.  If you are eating lots of refined foods and very little fruit and veg that could be the cause of your problems.

Read the section on food sensitivities where you will find information on a wide range of symptoms that can be connected with even healthy foods you have in your diet.  I have included my own story which is how I got into my current business.