Disorders of the Large and Small Intestines

Intestinal disorders can occur anywhere along the length of the gastrointestinal tract, from the mouth to the anus. The process of breaking down food begins in the mouth and continues in the stomach and small intestine. The small intestine is also where the body absorbs nutrients. The large intestine runs from the small intestine to the anus and is also responsible for the absorption of nutrients and water.

Common intestinal disorders such as diarrhea, constipation and flatulence affect most people at some point in their lives. Flatulence does not usually indicate a problem with the intestines, and is usually a normal side effect of the digestive process.

Constipation often can be traced to a lack of fiber in the diet. Severe constipation can cause rectal tears and intestinal blockages.

Diarrhea is not an intestinal disorder, but rather a symptom of intestinal disorders. Depending on the cause, diarrhea may be short-term and self-resolving, or a chronic intestinal condition requiring medical care.

Celiac disease is an immune system disorder that targets the small intestine. The immune system mistakes gluten (a protein found in wheat, rye, barley and oats) as a threat and responds by causing inflammation in the small intestine.

Crohn's disease is an inflammatory bowel disease. Not restricted to either the large or small intestine, Crohn's disease occurs at any point in the gastrointestinal tract, from the mouth to the anus.

Colon polyps commonly arise in the large intestine. Although they're typically non-cancerous, colon polyps can develop into colon cancer.

Diverticular disease can affect both the large and small intestines, although the disease is more common in the large intestine. Diverticular disease occurs when pouches develop in the intestinal wall.

Intestinal parasites include roundworms and tape worms, which can grow to great lengths in the intestines.

Irritable bowel syndrome affects the large intestine, causing colon muscles to contract too much. IBS results in cramping of the large intestine, gas, constipation and diarrhea.

Lactose intolerance is an inability to digest lactose, a sugar found in dairy products. Lactose intolerance affects the intestines by causing intestinal gas, cramping, and diarrhea.

Ulcerative colitis is an inflammatory bowel disease. Although it can develop throughout the intestines, ulcerative colitis is often limited to the large intestine.

This section is divided into multiple articles, covering topics such as diarrhea and malabsorption disorders, with each listed in the menu to the left. To research other gastrointestinal issues or health topics, please use the morefocus search tool, or see the related topics listed to the left.