Irritable bowel syndrome (IBS) is a group of symptoms including abdominal pain, bloating, diarrhea, and other discomforts caused by changes in how the gastrointestinal tract works. This disorder affects the muscle contraction of the colon (large intestine). Although it can be very uncomfortable and inconvenient, IBS does not lead to serious disease, such as cancer, and it does not permanently harm the large intestine. IBS is one of the most common disorders diagnosed by doctors, up to 20% of adults in the United States have symptoms of IBS. Certain foods may trigger IBS symptoms, so individuals with the condition must take note of the foods or beverages, such as caffeine, alcohol, fatty foods, and some non-nutritive sweeteners, that may cause difficulty. When diarrhea occurs, water consumption must be increased to avoid dehydration. An increase in dietary fiber can help deal with the symptom of constipation. Some medications are prescribed for individuals with IBS, and probiotics may be helpful for some people.

Inflammatory bowel disease (IBD) is a broad term that describes serious, chronic conditions that are caused by an abnormal response by the body’s immune system, which causes inflammation of the GI tract. The most common IBDs are ulcerative colitis and Crohn’s disease. In ulcerative colitis, the mucosa of the intestine becomes irritated and swollen and open wounds (ulcers) develop. Ulcerative colitis is often most severe in the lower colon (the rectum), which can cause diarrhea. Crohn’s disease most often affects the lower portions of the small intestine and parts of the large intestine. However, it can attack any part of the digestive tract.

Individuals with IBDs are at risk for serious or even life-threatening complications, such as bowel obstruction (caused by the narrowing of the intestinal wall); ulcers in the digestive track, including the mouth and anus; fistulas (an abnormal connection between the intestine and skin or other organs); malnutrition because of poor absorption; colon cancer; and problems in parts of the body outside of the GI tract, such as kidney stones or arthritis. A person with IBD needs a nourishing diet to deal with potential nutrient deficiencies brought about by absorption issues, as well as assistance when significant weight loss occurs. People suffering with IBDs are treated with anti-inflammatory drugs, and often require surgical procedures to deal with medical complications.