Digestive Problems
Digestion is the process by which food is broken down into smaller pieces so that the body can use them to build and nourish cells and to provide energy. Digestion involves the mixing of food, its movement through the digestive tract (also known as the alimentary canal), and the chemical breakdown of larger molecules into smaller molecules.
Every piece of food we eat has to be broken down into smaller nutrients that the body can absorb, which is why it takes hours to fully digest food. The digestive system is made up of the digestive tract. This consists of a long tube of organs that runs from the mouth to the anus and includes the oesophagus, stomach , small intestine, and large intestine, together with the liver, gall bladder, and pancreas, which produce important secretions for digestion that drain into the small intestine. The digestive tract in an adult is about 30 feet long.
Digestion begins in the mouth, where chemical and mechanical digestion occurs. Saliva or spit, produced by the salivary glands (located under the tongue and near the lower jaw), is released into the mouth. Saliva begins to break down the food, moistening it and making it easier to swallow. A digestive enzyme (called amylase) in the saliva begins to break down the carbohydrates (starches and sugars). One of the most important functions of the mouth is chewing.
Chewing allows food to be mashed into a soft mass that is easier to swallow and digest later. Movements by the tongue and the mouth push the food to the back of the throat for it to be swallowed. A flexible flap called the epiglottis closes over the trachea (windpipe) to ensure that food enters the oesophagus and not the windpipe to prevent choking. Once food is swallowed, it enters the oesophagus, a muscular tube that is about 10 inches long. The oesophagus is located between the throat and the stomach . Muscular wavelike contractions known as peristalsis push the food down through the oesophagus to the stomach .
A muscular ring (called the cardiac sphincter) at the end of the oesophagus allows food to enter the stomach , and, then, it squeezes shut to prevent food and fluid from going back up the oesophagus. The stomach is a J-shaped organ that lies between the oesophagus and the small intestine in the upper abdomen. The stomach has 3 main functions: to store the swallowed food and liquid; to mix up the food, liquid, and digestive juices produced by the stomach; and to slowly empty its contents into the small intestine. Only a few substances, such as water and alcohol, can be absorbed directly from the stomach . Any other food substances must undergo the digestive processes of the stomach . The stomach´s strong muscular walls mix and churn the food with acids and enzymes (gastric juice), breaking it into smaller pieces. About 3 quarts of the gastric juice is produced by glands in the stomach every day. The food is processed into a semi-liquid form called chyme. About 4 hours or so after eating a meal, the chyme is slowly released a little at a time through the pyloric sphincter, a thickened muscular ring between the stomach and the first part of the small intestine called the duodenum.
Most digestion and absorption of food occurs in the small intestine. The small intestine is a narrow, twisting tube that occupies most of the lower abdomen between the stomach and the beginning of the large intestine. It extends about 20 feet in length. The small intestine consists of 3 parts: the duodenum (the C-shaped part), the jejunum (the coiled midsection), and the ileum (the last section). The small intestine has 2 important functions. First, the digestive process is completed here by enzymes and other substances made by intestinal cells, the pancreas, and the liver. Glands in the intestine walls secrete enzymes that breakdown starches and sugars. The pancreas secretes enzymes into the small intestine that help breakdown carbohydrates, fats, and proteins. The liver produces bile, which is stored in the gallbladder. Bile helps to make fat molecules (which otherwise are not soluble in water) soluble, so they can be absorbed by the body. Second, the small intestine absorbs the nutrients from the digestive process. The inner wall of the small intestine is covered by millions of tiny fingerlike projections called villi. The villi are covered with even tinier projections called microvilli. The combination of villi and microvilli increase the surface area of the small intestine greatly, allowing absorption of nutrients to occur. Undigested material travels next to the large intestine. The large intestine forms an upside down U over the coiled small intestine. It begins at the lower right-hand side of the body and ends on the lower left-hand side. The large intestine is about 5-6 feet long. It has 3 parts: the cecum, the colon, and the rectum. The cecum is a pouch at the beginning of the large intestine. This area allows food to pass from the small intestine to the large intestine. The colon is where fluids and salts are absorbed and extends from the cecum to the rectum.
The last part of the large intestine is the rectum, which is where faeces (waste material) is stored before leaving the body through the anus. The main job of the large intestine is to remove water and salts from the undigested material and to form solid waste that can be excreted. Bacteria in the large intestine help to break down the undigested materials. The remaining contents of the large intestine are moved toward the rectum, where faeces are stored until they leave the body through the anus as a bowel movement Digestive System Problems Nearly everyone has a digestive problem at one time or another. Some conditions, such as indigestion or mild diarrhoea, are common; they result in mild discomfort and get better on their own or are easy to treat. Others, such as inflammatory bowel disease, can be long lasting or troublesome. A doctor who specializes in the digestive system is called a GI specialist or gastroenterologist Problems With the Oesophagus Problems affecting the oesophagus may be congenital (present at birth) or nonc-ongenital (developed after birth). Examples include: Congenital conditions: Tracheoesophageal fistula is a connection between the oesophagus and the trachea (windpipe) where there shouldn't be one. In babies with oesophageal atresia, the oesophagus comes to a dead end instead of connecting to the stomach. Both conditions are usually detected soon after a baby is born — sometimes even before — and require surgery to repair. Non-congenital conditions: Oesophagitis (inflammation of the oesophagus) can be caused by infection, certain medications, or gastroesophageal reflux disease (GERD). With GERD, the oesophageal sphincter (the valve that connects the oesophagus with the stomach) doesn't work well and allows the acidic contents of the stomach to move backward up into the oesophagus. GERD often can be corrected through lifestyle changes, such as dietary adjustments. Sometimes, though, it requires treatment with medication.
Problems with the Stomach and Intestines: Almost everyone has experienced diarrhoea or constipation. With diarrhoea, muscle contractions move the contents of the intestines along too quickly and there isn't enough time for water to be absorbed before the faeces are pushed out of the body. Constipation is the opposite: The contents of the large intestines do not move along fast enough and waste materials stay in the large intestine so long that too much water is removed and the faeces become hard. Other common stomach and intestinal disorders include: Gastrointestinal infections can be caused by viruses, by bacteria (such as Salmonella, Shigella, Campylobacter, or E. coli), or by intestinal parasites (such as amebiasis and giardiasis). Abdominal pain or cramps, diarrhoea, and sometimes vomiting are the common symptoms of gastrointestinal infections. These usually go away on their own without medicines or other treatment. Appendicitis, an inflammation of the appendix, most often affects kids and teens between 11 and 20 years old, and requires surgery to correct. The classic symptoms of appendicitis are abdominal pain, fever, loss of appetite, and vomiting. Gastritis and peptic ulcers arise when a bacterium, Helicobacter pylori, or the chronic use of drugs or certain medications weakens the protective mucous coating of the stomach and duodenum, allowing acid to get through to the sensitive lining beneath. This can irritate and inflame the lining of the stomach (gastritis) or cause peptic ulcers, which are sores or holes in the lining of the stomach or the duodenum that cause pain or bleeding. Medications usually successfully treat these conditions. Inflammatory bowel disease (IBD) is chronic inflammation of the intestines that affects older kids, teens, and adults. There are two major types: ulcerative colitis, which usually affects just the rectum and the large intestine; and Crohn's disease, which can affect the whole gastrointestinal tract from the mouth to the anus as well as other parts of the body. They are treated with medications and, if necessary, intravenous (IV) feedings to provide nutrition. In some cases, surgery may be necessary to remove inflamed or damaged areas of the intestine. Celiac disease is a disorder in which the digestive system is damaged by the response of the immune system to a protein called gluten, which is found in wheat, rye, and barley and a wide range of foods, from breakfast cereal to pizza crust. People with celiac disease have difficulty digesting the nutrients from their food and may experience diarrhoea, abdominal pain, bloating, exhaustion, and depression when they eat foods with gluten. Symptoms can be managed by following a gluten-free diet. Celiac disease runs in families and can become active after some sort of stress, such as surgery or a viral infection. A doctor can diagnose celiac disease with a blood test and by taking a biopsy of the small intestine. Irritable bowel syndrome (IBS), a common intestinal disorder, affects the colon and may cause recurrent abdominal cramps, bloating, constipation, and diarrhoea. There is no cure, but IBS symptoms may be treated by changing eating habits, reducing stress, and making lifestyle changes. A doctor may also prescribe medications to relieve diarrhoea or constipation. No one test is used to diagnose IBS, but a doctor may identify it based on symptoms, medical history, and a physical exam. Problems With the Pancreas, Liver, and Gallbladder: Conditions affecting the pancreas, liver, and gallbladder often affect the ability of these organs to produce enzymes and other substances that aid in digestion. Examples include: Cystic fibrosis is a chronic, inherited illness where the production of abnormally thick mucus blocks the ducts or passageways in the pancreas and prevents its digestive juices from entering the intestines, making it difficult to properly digest proteins and fats. This causes important nutrients to pass out of the body unused. To help manage their digestive problems, people with cystic fibrosis can take digestive enzymes and nutritional supplements. Hepatitis, a condition with many different causes, is when the liver becomes inflamed and may lose its ability to function. Viral hepatitis, such as hepatitis A, B, or C, is highly contagious. Mild cases of hepatitis A can be treated at home; however, serious cases involving liver damage may require hospitalization. The gallbladder can develop gallstones and become inflamed — a condition called cholecystitis. Although gallbladder conditions are uncommon in kids and teens, they can occur in those who have sickle cell anaemia or are being treated with certain long-term medications.
Keeping Digestion on Track: The kinds and amounts of food a person eats and how the digestive system processes that food play key roles in maintaining good health. Eating a healthy diet is the best way to prevent common digestive problems. For specific information on digestive problems see: Constipation, Diarrhoea, Dyspepsia, Indigestion, Irritable Bowel Syndrome, Sluggish Digestion, Stomach Pains
