ileum extends from the JEJUNUMto the CECUM. The
ileum absorbs fats and fat-soluble vitamins as well
as other remaining NUTRIENTSfrom the digestive
content, which it then passes through the ileoce-
cal valve into the cecum (the first segment of the
COLON). Like the other segments of the small intes-
tine, the ileum’s walls contain extensive villi (fin-
gerlike projections) that expand its surface area to
increase its ability to absorb nutrients.
CONDITIONS THAT CAN AFFECT THE ILEUM
Crohn’s disease ILEUS
INTESTINAL ADHESIONS LYMPHOMA
MALABSORPTION SHORT BOWEL SYNDROME
For further discussion of the ileum and the
small intestine within the context of gastrointesti-
nal structure and function, please see the
overview section “The Gastrointestinal System.”
See also DUODENUM; ILEOANAL RESERVOIR;
ILEOSTOMY; MINERALS AND HEALTH; VITAMINS AND
HEALTH; NUTRITIONAL NEEDS.
ileus An obstruction or blockage of the intestinal
tract. Ileus is potentially life-threatening and may
require emergency surgery. Common causes
include
- INTESTINAL ADHESIONS
- tumors (benign or malignant)
- swallowed objects
- severe FECAL IMPACTION
•a BEZOAR that moves into the intestinal tract
from the STOMACH
Symptoms include ABDOMINAL PAIN, VOMITING,
DIARRHEA, and failure to have bowel movements.
Typically BOWEL SOUNDSare absent in the intestinal
tract beyond the obstruction, and the abdomen is
rigid. The diagnostic path may include abdominal
X-RAY, ULTRASOUND, or laparoscopic surgery. Treat-
ment is nearly always surgery to remove the
obstruction, often laparoscopic though sometimes
OPEN SURGERYis necessary. Delays in surgery can
result in tissue necrosis (death), requiring the sur-
geon to reconstruct a portion of the bowel and
increasing the risk of INFECTION.
See also APPENDICITIS; BOWEL MOVEMENT; INTUSSUS-
CEPTION; MINIMALLY INVASIVE SURGERY; PERITONITIS.indigestion See DYSPEPSIA.inflammatory bowel disease (IBD) A chronic
disorder in which INFLAMMATION develops along
segments of the gastrointestinal tract. There are
two forms of IBD, Crohn’s disease and ulcerative
colitis. Crohn’s disease can affect any portion of
the intestinal tract though most commonly
involves the lower SMALL INTESTINE and upper
COLON. Ulcerative colitis affects the colon including
theRECTUM. Doctors and researchers believe IBD is
an autoimmune disorder in which the IMMUNE SYS-
TEMmay create antibodies that attack the intes-
tinal mucosa (mucus lining of the intestinal walls).
Researchers have detected several GENEmutations
that correlate to Crohn’s disease, and both Crohn’s
disease and ulcerative colitis have strong familial
tendencies. Doctors consider the two conditions
collectively because the disease processes, symp-
toms, and treatments overlap, though each condi-
tion has unique clinical features.
Symptoms and Diagnostic Path
Both forms of IBD generate ulcerative sores in the
intestinal mucosa that cause irritation and inflam-
mation. The resulting symptoms may include- DIARRHEA, often bloody when IBD involves the
colon - rectal bleeding
- ABDOMINAL PAIN, sometimes intense
- unintended weight loss
- fatigue
- FEVER
The inflammation and bleeding typically result
in ANEMIA, which is one reason for the fatigue.
Other systemic changes related to the autoim-
mune disease process further contribute to fatigue.
Alternating periods of symptoms and REMISSION
characterize IBD. When IBD is in remission, gas-
trointestinal function is normal. When the disease
is active, often referred to as an “attack,” the
severity of symptoms may range from manageable
to debilitating.inflammatory bowel disease (IBD) 61