Skip to main content


  • Failure to Thrive (FTT): A general term used for insufficient growth (by standard growth charts) or inadequate weight gain caused by a variety of medical and psychosocial conditions.
  • Fat: A dietary substance that is broken down in the body to fatty acids. See also EFA.
  • FDA: See Food and Drug Administration.
  • Fecal Impaction: When feces, or stool, obstructs colon or rectum, and does not allow waste to pass. It is most commonly seen in people with long-term constipation, and can cause bloating and abdominal pain. This condition usually requires a stool softener or manual disimpaction to alleviate the problem.
  • Fibrosis: The formation of excess fibrous tissue, usually in response to damage or injury.
  • Fistula: An abnormal tract formed between loops of bowel, the bowel and other organs or the bowel and the skin surface. Fistulas are normally associated with severe Crohn's Disease, but might also occur with other inflammatory conditions. Antibiotics and anti-inflammatory medications are typically required for treatment, and placement of a drain or surgical treatment may also be necessary.
  • Flare: A time during which active disease is present.
  • Flatulence: Passing gas through the anus. May be accompanied by bloating, indigestion and/or other symptoms.
  • Flexible Sigmoidoscope:  See Sigmoidoscope.
  • Flexible Sigmoidoscopy: See Sigmoidoscopy.
  • Flexure: A normal bend in a tubular body structure such as the large intestines.
  • Fluticasone Propionate: A corticosteroid medication that helps reduce inflammation.
  • Food and Drug Administration (FDA): A United States federal agency that is responsible for protecting the public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, medical devices, the Nation's food supply, cosmetics, and products that emit radiation.
  • Food Challenge: Exposure to a food with the aim of determining whether it will elicit an immunological or clinical response.
  • Food Trial: Relative to EGID, the introduction/reintroduction of a food, typically for a specified period of time and subsequently evaluated via endoscopy, with the aim of determining whether it is considered to be a “food trigger,” resulting in clinical symptoms and/or histological abnormalities (i.e., eosinophil-predominant inflammation).
  • FP: See Fluticasone Propionate.
  • FTT: See Failure to Thrive.
  • Furrowing: Longitudinal linear creases in the esophagus.