A swollen, tender belly and diarrhea can be uncomfortable, to say the least. There are several things that can cause such symptoms, and getting to the bottom of them is the first and most important step in recovery. In some cases, these symptoms can be attributed to something simple.

To extract nutrients from the foods you eat, they must be small enough for the cells of your small intestine to absorb. The process of digestion reduces your food particles to a size sufficient for absorption to occur.

There are many possible causes of chronic diarrhea, which is defined as having watery, liquid or semisolid bowel movements for more than 4 weeks. Losing weight at the same time can mean that food is moving too quickly through your digestive system without proper digestion or absorption.

Flatulence, often referred to as passing gas, is a normal part of the digestive process. It helps to release gas that gets built up in your large intestine, often as a result of consuming a gas-producing food such as beans.

Experiencing stomach cramps while doing situps might make you want to give up working your abdominal muscles altogether. Cramps can be painful, and sometimes linger for several minutes.

Creatine is a biological compound located predominantly in your muscle tissue. Classified as a nitrogen-containing organic acid, creatine supplies your muscles with energy through its interaction with adenosine triphosphate, or ATP.

Gas is a normal part of life, but excessive gas accompanied by an upset stomach might interfere with daily life. The inability to expel gas can lead to intense stomach pains. Although gas cannot be prevented, you can reduce the amount of gas you produce.

The time it takes for food to digest varies per person and is affected by how much food was eaten, the combination of foods, physical activity and metabolism.

Roughly 30 percent of adults in the United States experienced joint pain or stiffness in 2006, according to a National Health Interview Survey. The most common cause is arthritis -- the term for chronic joint inflammation.

Constipation is a common medical problem, the most common cause of which is inadequate dietary fiber intake, often coupled with insufficient exercise. Chronic constipation frequently causes abdominal pain.

Stomach bloating, sometimes called belly bloat, is any abnormal increase in the diameter of your abdomen due to the build up of gas. Some air enters your stomach and intestines through the act of eating and drinking, but most gas is produced by the friendly bacteria in your large intestine.

If you have experienced acid reflux, as most people have, you have probably felt a burning sensation in the area of the breastbone, or maybe it even extended up into your throat. You may also have noticed an acidic, sour taste in the back of your mouth. These are common symptoms of acid reflux.