Webster's New World Medical Dictionary

iris, speckled
See 
Brushfield spot.
iritis
Inflammation of the iris. Iritis can be asso-
ciated with an autoimmune disease such as rheuma-
toid arthritis or lupus. It can also occur as a result
of infection, other inflammatory conditions, or
injury.
iron
A mineral that is necessary for the transport
of oxygen via hemoglobin in red blood cells and for
the oxidation process in cells by cytochromes. Food
sources of iron include meat, poultry, eggs, vegeta-
bles, and cereals, especially those fortified with
iron. See also 
deficiency, iron; excess iron; iron
poisoning.
iron deficiency
See 
deficiency, iron.
iron excess
See 
excess iron.
iron poisoning
An abnormally excessive inges-
tion of iron resulting in injury to body tissues. Iron
supplements meant for adults, such as pregnant
women, are a major cause of poisoning in children.
Children should never be given supplements or
multivitamins containing iron unless they have been
prescribed by a physician, and iron preparations for
adults should be kept away from children. See also
hemochromatosis
.
irrigate
To wash out. For example, one can irri-
gate a wound to clean it.
irrigation of the colon
The use of liquid solu-
tions given by enema to remove material from the
rectum or colon, ostensibly to eliminate toxins from
the bowel. Unless ordered by a physician, irrigation
of the colon is rarely advisable. Irrigation of the
colon carries a number of risks, including interfer-
ence with the normal digestive process and perfora-
tion. Also known as colonic irrigation and high
colonics.
irritable bowel syndrome
A functional intes-
tinal disorder of the bowels and their nerves.
Irritable bowel syndrome (IBS) may be caused by
either abnormal motility (abnormal contractions)
of the intestinal muscles or abnormally sensitive
nerves in the intestines (visceral hyper-sensitivity).
IBS is characterized by abdominal pain, bloating,
mucus in stools, and irregular bowel habits, with
alternating diarrhea and constipation. These symp-
toms tend to be chronic, and they wax and wane
over the years. Although IBS can cause chronic and
recurrent discomfort, it does not normally lead to