Hemochromatosis - a genetic condition that causes the body to absorb and store too much iron. While many individuals with this disease have no symptoms, injuries to the liver can slowly lead to cirrhosis if the illness is not treated.

Hiatus hernia- It is the protrusion of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm. The symptoms include acid reflux, and pain, similar to heartburn, in the chest and upper stomach. For most people, hiatus hernias cause no symptoms. Sometimes patients experience heartburn and regurgitation, when stomach acid refluxes back into the esophagus.

In most cases, sufferers experience no discomfort and no treatment is required. However, when the Hiatus hernia is large, or is to close to the esophagus, it is likely to cause esophageal stricture and discomfort. Symptomatic patients should elevate the head of their beds and avoid lying down directly after meals until treatment is rendered. If the condition has been brought on by stress, stress reduction techniques may be prescribed, or if overweight, weight loss may be indicated. Anti-secretory drugs can be used to reduce acid secretion.

Pancreatitis – it is an inflammation or infection of the pancreas -- an elongated, tapered gland that is located behind the stomach. The pancreas secretes digestive enzymes and the hormones insulin and glucagon. The various types of pancreatitis involve irritation, inflammation, and infection of the pancreas. The disorders differ according to whether symptoms develop suddenly or slowly.

How is the digestive process controlled?

Hormone Regulators - A fascinating feature of the digestive system is that it contains its own regulators. The major hormones that control the functions of the digestive system are produced and released by cells in the mucosa of the stomach and small intestine. These hormones are released into the blood of the digestive tract, travel back to the heart and through the arteries, and return to the digestive system, where they stimulate digestive juices and cause organ movement.

Nerve Regulators - Two types of nerves help to control the action of the digestive system. Extrinsic (outside) nerves come to the digestive organs from the unconscious part of the brain or from the spinal cord. They release a chemical called acetylcholine and another called adrenaline. Acetylcholine causes the muscle of the digestive organs to squeeze with more force and increase the "push" of food and juice through the digestive tract. Acetylcholine also causes the stomach and pancreas to produce more digestive juice. Adrenaline relaxes the muscle of the stomach and intestine and decreases the flow of blood to these organs.

Even more important, though, are the intrinsic (inside) nerves, which make up a very dense network embedded in the walls of the esophagus, stomach, small intestine, and colon. The intrinsic nerves are triggered to act when the walls of the hollow organs are stretched by food. They release many different substances that speed up or delay the movement of food and the production of juices by the digestive organs.

The large, hollow organs of the digestive system contain muscle that enables their walls to move. The movement of organ walls can propel food and liquid and also can mix the contents within each organ. Typical movement of the esophagus, stomach, and intestine is called peristalsis. The action of peristalsis looks like an ocean wave moving through the muscle. The muscle of the organ produces a narrowing and then propels the narrowed portion slowly down the length of the organ. These waves of narrowing push the food and fluid in front of them through each hollow organ.

The first major muscle movement occurs when food or liquid is swallowed. Although we are able to start swallowing by choice, once the swallow begins, it becomes involuntary and proceeds under the control of the nerves.

The esophagus is the organ into which the swallowed food is pushed. It connects the throat above with the stomach below. At the junction of the esophagus and stomach, there is a ring like valve, called cardiac valve, closing the passage between the two organs. However, as the food approaches the closed ring, the surrounding muscles relax and allow the food to pass.

The food then enters the stomach, which has three mechanical tasks to do. First, the stomach must store the swallowed food and liquid. This requires the muscle of the upper part of the stomach to relax and accept large volumes of swallowed material. The second job is to mix up the food, liquid, and digestive juice produced by the stomach. The lower part of the stomach mixes these materials by its muscle action. The third task of the stomach is to empty its contents slowly into the small intestine. Another valve, called the pylorus prevents the movement of the food to the duodenum until it is ready.

Several factors affect emptying of the stomach, including the nature of the food (mainly its fat and protein content) and the degree of muscle action of the emptying stomach and the next organ to receive the contents (the small intestine). After the food moves from the duodenum, it is digested in the small intestine and dissolved into the juices from the pancreas, liver, and intestine. The contents of the intestine are then mixed and pushed forward to allow further digestion.

Finally, all of the digested nutrients are absorbed through the intestinal walls. The waste products of this process include undigested parts of the food, known as fiber, and older cells that have been shed from the mucosa. These materials are propelled into the colon, where they remain, usually for a day or two, until the feces are expelled by a bowel movement.