I

Idiopathic
Of, relating to, or designating a disease having unknown cause.

Ileostomy
Pronounced – il-ee-AW-stuh-mee
Ileostomy is a surgery to remove the entire large intestine and connect the bottom of the small intestine (ileum) to a hole in the abdomen. This hole in the abdomen is called a stoma. Stool leaves the body through the stoma, instead of through the anus, and goes into a bag attached to the skin around the stoma. This bag must be emptied several times a day.

Ileum
Pronounced – il-ee-um
The lower end of the small intestine.

Immune System
The collection of cells and organs whose role is to protect the body from foreign invaders. Includes the thymus, spleen, lymph nodes, B and T cells, and antigen-presenting cells.

Immunocompromised
Having an immune system that has been impaired by disease or treatment.

Immunoglobulin G (IgG)
An antibody containing substance produced by human plasma cells in diseased central nervous system plaques. Levels of IgG are increased in the cerebrospinal fluid of most MS patients.

Immunosuppression
Pronounced – IH-myoo-noh-suh-PREH-shun
Suppression of the immune system functions and its ability to fight infections and other diseases. Many medications under investigation for the treatment of MS are immunosuppressants.

Immunosuppressive
Pronounced – IH-myoo-noh-suh-PREH-siv
Describes the ability to decrease the body’s immune system responses.

Incontinence
The inability to control the flow of urine from the bladder, called urinary incontinence, or the escape of stool from the rectum, called bowel incontinence or fecal incontinence.

Inflame
To cause to redden or grow hot.

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

Inflammatory
Causing inflammation.

Inflammatory Bowel Disease (IBD)
Pronounced – in-FLAM-uh-toh-ree BAH-wul duh-zeez
Long lasting problems that cause irritation and ulcers in the Gastrointestinal (GI) Tract. The most common disorders are ulcerative colitis and Crohn’s disease.

Inherit
In genetics (genetics is the study of inheritance patterns of specific traits), to receive genetic material from your parents through biological processes.

Insoluble Fiber
Insoluble fiber often called roughage, does not dissolve in water, passes essentially unchanged through the intestines and produces little gas. Insouble fiber helps move waste through the digestive tract decreasing the time that potentially harmful substances may stay in the colon. Found in wheat bran and some vegetables.

Interferon
Pronounced – in-ter-FEER-on
A biological response modifier (a substance that can improve the body’s natural response to infections and other diseases). Interferons interfere with the division of cancer cells and can slow tumor growth. There are several types of interferons, including interferon-alpha, -beta, and -gamma. The body normally produces these substances. They are also made in the laboratory to treat cancer and other diseases.

Intermittent
Stopping and starting at intervals, recurring or reappearing from time to time.

Intestinal Pseudo-Obstruction
Pronounced – in-TES-tuh-nul SOO-doh ub-STRUK-shun
A disorder that causes symptoms of blockage, but when the intestines are examined, no blockage is found. Causes constipation, vomiting, and pain.

Intestine
Pronounced – in-TESS-tin
The long, tube-shaped organ in the abdomen that completes the process of digestion. Also called the bowel. There are both large and small intestines.

Intravenous (IV)
Pronounced – IN-truh-VEE-nus
Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or tube inserted into a vein. Also called I.V.

Irritable Bowel Syndrome (IBS)
Pronounced – EER-uh-tuh-bul BAH-wul sin-drohm
A disorder that comes and goes. Nerves that control the muscles in the Gastrointestinal (GI) Tract are too active. The Gastrointestinal (GI) Tract becomes sensitive to food, stool, gas, and stress. Causes abdominal pain, bloating, and constipation or diarrhea. Also called spastic colon or mucous colitis.

I.V.
Into or within a vein. I.V. usually refers to a way of giving a drug or other substance through a needle or tube inserted into a vein. Also called intravenous.