Most people will experience gastrointestinal problems of some kind at least once. These types of disorders affect one or more structures in the digestive system, which includes the esophagus, stomach, intestines, colon, and rectum. Common gastrointestinal problems include constipation, diarrhea, hemorrhoids, gastroenteritis, colitis, and irritable bowel disorders.

The most common gastrointestinal problems, diarrhea and constipation, are common symptoms of many digestive disorders, but may also exist without underlying disease. In such cases, these are often caused by stress, inadequate exercise, routine changes, or medication. Both diarrhea and constipation may also be caused by dietary changes or inadequacies. Diarrhea, for example, may be the result of eating too much fiber or of eating foods to which one is allergic, while constipation can result from too little fiber or from overeating dairy products.

Diarrhea and constipation may also signify the presence of a more serious digestive disorder. For example, irritable bowel syndrome may cause diarrhea or constipation, or both, in addition to abdominal pain, bloating, and gas. Many people with irritable bowel syndrome benefit from increasing the amount of fiber they eat, avoiding foods which trigger symptoms, and reducing stress.

Hemorrhoids are a common gastrointestinal problem which may result from chronic diarrhea or constipation. Hemorrhoids, which are swollen blood vessels, form due to chronic pressure exerted during strained bowel movements. They may form inside or outside the rectum. When outside they lie just under the skin, and may burst and form a blood clot. If located inside the rectum, they may bleed and become inflamed and irritated. People with hemorrhoids can help alleviate these problems by stabilizing their bowel habits to reduce the amount of straining they do. An improved diet, with the right amount of fiber, is another useful way to manage these types of gastrointestinal problems.

Gastroenteritis and colitis are inflammatory gastrointestinal problems in which sections of the digestive tract become chronically inflamed. In colitis, for example, the bowel becomes irritated and inflamed, leading to abdominal cramping, diarrhea, rectal bleeding, and irregular bowel habits. These inflammatory digestive disorders may have a variety of causes. For example, the disorder may be caused by an infectious agent, stomach ulcers, a side effect of radiation treatment for cancer, or a symptom of reduced blood supply to the affected area.

Colon polyps are a benign gastrointestinal disorder, but polyps may become cancerous if left untreated. Most cases of colon cancer begin as a benign polyp, a small growth of skin which forms in the colon or rectum. Only a relatively small proportion of polyps can turn cancerous, but the polyps themselves are common. Colon cancer can spread quickly if a precancerous polyp is not removed before cancer develops. In most cases, removal of a precancerous polyp can prevent cancer from occurring at that spot.