Glossary I

I

Ileostomy

A surgically created opening of the abdominal wall to the ileum, allowing the diversion of fecal waste.

Ileum

The lower third of the small intestine, adjoining the colon.

Illness

A subjective state of feeling unwell that may include impairment of normal physiological and social function.

Imaging

Tests that produce pictures of areas inside the body.

Imperforate anus

A birth defect in which the anal canal fails to develop, treated surgically.

Incidence

Describes the occurrence of a disease or disorder in a population. It is a rate, showing how many new cases of a disease occurred in a population (typically a susceptible population called the "at-risk population" ) during a specified interval of time (usually expressed as number of new cases per unit time per fixed number of people; e.g., number of new cases per 1,000 persons in one year).

Inflammation

Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.

Inflammatory bowel disease (IBD)

Long-lasting problems that cause irritation and ulcers in the gastrointestinal tract. The most common disorders are ulcerative colitis and Crohn's disease.

Ingestion

Taking into the body by mouth.

Inherited

Transmitted through genes from parents to offspring.

Innervated

A structure supplied with intact nerves.

Institutional review board (IRB)

In the U.S. a group of scientists, doctors, clergy, and consumers at each health care facility that participates in a clinical trial. IRBs are designed to protect study participants. They review and must approve the action plan for every clinical trial. They check to see that the trial is well designed, does not involve undue risks, and includes safeguards for patients.

Interstitial cells of Cajal (ICC)

Specialized cells found throughout the gastrointestinal tract that are required for normal gastrointestinal motility.

Interstitial cystitis

A long-lasting condition also known as painful bladder syndrome or frequency-urgency-dysuria syndrome. The wall of the bladder becomes inflamed or irritated, which affects the amount of urine the bladder can hold and causes scarring, stiffening, and bleeding in the bladder.

Intervention

Anything meant to change the course of events for someone (e.g., drug, surgery, test, treatment, counseling, etc.)

Intestinal

Relating to or occuring in the intestines.

Intestinal mucosa

The surface lining of the intestines where the cells absorb nutrients.

Intestinal permeability

The barrier properties of the lining of the intestines, which prevent harmful substances from passing through into the body.

Intestinal pseudo-obstruction

A motility disorder with symptoms like those of a bowel blockage, but with no physical evidence of blockage or obstruction. Symptoms may include cramps, stomach pain, nausea, vomiting, bloating, fewer bowel movements than usual, and loose stools.

Intestines

Also known as the gut or bowels, is the long, tube-like organ in the human body that completes digestion or the breaking down of food. They consist of the small intestine and the large intestine.

Intractable

Symptoms that don't respond to usual treatments.

Investigational

In U.S. clinical trials, refers to a drug (including a new drug, dose, combination, or route of administration) or procedure that has undergone basic laboratory testing and received approval from the Food and Drug Administration (FDA) to be tested in human subjects. A drug or procedure may be approved by the FDA for use in one disease or condition, but be considered investigational in other diseases or conditions. Also called experimental.

Investigational New Drug Application (IND)

A petition to the FDA to allow testing of a new drug in clinical trials.

In vitro

In the laboratory (outside the body). The opposite of in vivo (in the body).

In vivo

In the body. The opposite of in vitro (outside the body or in the laboratory).

Irritable bowel syndrome

A functional bowel disorder in which abdominal discomfort or pain is associated with defecation or a change in bowel habit, and with features of disordered defecation.

Ischemic colitis

Inflammation of the large intestine (colon) caused by decreased blood flow to the colon. Symptoms may include: abdominal pain, fever, vomiting, blood in the stool, diarrhea, low back pain.