The Digestive system
L4
Dr.ghada mansoor
Inflammatory Bowel Disease (IBD)
IBD
represent two disorders of idiopathic chronic intestinal inflammation: Crohn
disease and ulcerative colitis.
Both disorders are characterized by unpredictable exacerbations and remissions.The
onset is during adolescence and young adulthood. IBD is more common in urban
areas than in rural areas.
Both genetic and environmental influences are involved in the pathogenesis of IBD.
The risk in family members of an affected individual in the range of 7-22%; a child
whose parents both have IBD has a greater than 35% chance of acquiring the
disorder. A perinuclear antineutrophil antibody (pANCA) is found in about 70% of
individuals with ulcerative colitis compared with less than 20% of those with Crohn
disease.
Cigarette smoking is a risk factor for Crohn disease but paradoxically protects against
ulcerative colitis.
Extraintestinal manifestations occur slightly more commonly with Crohn disease
than with ulcerative colitis.
Chronic Ulcerative Colitis
Ulcerative colitis is localized to the colon and spares the upper gastrointestinal tract.
Disease usually begins in the rectum and extends proximally for a variable distance.
When it is localized to the rectum, the disease is ulcerative proctitis, whereas
disease involving the entire colon is pancolitis.
Men are slightly more likely to acquire ulcerative colitis than are women; the reverse
is true for Crohn disease.
Clinical Manifestations
Blood, mucus, and pus in the stool as well as diarrhea are the typical presentation of
ulcerative colitis. Constipation may be observed in those with proctitis. tenesmus,
urgency, cramping abdominal pain are common.
The onset may range from insidious with gradual progression of symptoms to
fulminant.
Fulminant colitis defined as Fever, severe anemia, hypoalbuminemia, leukocytosis,
and greater than five bloody stools per day for 5 days.
Anorexia, weight loss, and growth failure may be present.
The use of nonsteroidal anti-inflammatory drugs is predisposing to exacerbation. The
risk of colon cancer begins to increase after 8-10 yr of disease and may then increase
by 0.5-1% per yr. Because colon cancer is usually preceded by changes of mucosal
dysplasia, it is recommended that patients who have ulcerative colitis for more than
10 yr be screened with colonoscopy and biopsy every 1-2 yr.
Extraintestinal manifestations that tend to occur more commonly with ulcerative
colitis than with Crohn disease include:
1. pyoderma gangrenosum,
2. sclerosing cholangitis & chronic active hepatitis
3. ankylosing spondylitis.
4. Iron deficiency may result from chronic blood loss as well as decreased intake.
5.Folate deficiency is unusual but may be accentuated in children treated with
sulfasalazine, which interferes with folate absorption.
6. Anemia of chronic disease.
7. Secondary amenorrhea is common during periods of active disease in older girls.
Diagnosis
1. Typical presentation in the absence of an identifiable specific cause
2. Laboratory studies
CBP: anemia (either iron deficiency or the anemia of chronic disease), WBC ↑ with
more severe colitis.
ESR & C-reactive protein: elevated.
Hypoalbuminemia.
3. Plain radiographs of the abdomen: may demonstrate loss of haustral markings in
an air-filled colon or marked dilatation with toxic megacolon.
4. Barium enema.
5. Sigmoidoscopy & colonoscopy with biopsy : Classically, disease starts in the
rectum with a gross appearance characterized by erythema, edema, loss of vascular
pattern, granularity, and friability. The endoscopic findings of ulcerative colitis result
from microulcers.
With very severe chronic colitis, pseudopolyps may be seen.
A colonoscopy should not be performed when fulminant colitis is suspected because
of the risk of provoking toxic megacolon or causing a perforation during the
procedure.
Biopsy → typical findings are cryptitis,& crypt abscesses.
Treatment
A medical cure for ulcerative colitis is not available; treatment is aimed at controlling
symptoms and reducing the risk of recurrence.
In mild colitis :
1.
* Aminosalicylate
1. Sulfasalazine: is composed of a sulfur moiety linked to the active ingredient 5-
aminosalicylate. This linkage prevents the premature absorption of the medication
in the upper gastrointestinal tract, allowing it to reach the colon, where the two
components are separated by bacterial cleavage.
The dose is 50-75 mg/kg/24 hr (divided into 2-4 doses) PO. Onset of action may take
several weeks.
2. Other less allergenic preparations of 5-aminosalicylate (mesalamine, 40-60
mg/kg/day) to treat ulcerative colitis and prevent recurrences.
Aminosalicylate may also be given in enema form and is especially useful for
proctitis.
Hydrocortisone enemas (100 mg) are used to treat proctitis, once a day (usually
bedtime) for 2-3 wk.
2. I n moderate to severe pancolitis or colitis that is unresponsive to 5-
aminosalicylate therapy treated with oral corticosteroids (prednisone) . The dose is
1-2 mg/kg/24 hr, taper to an alternate-day dose within 1-3 mo.
Children who requiring frequent corticosteroid therapy are started on
immunomodulators such as azathioprine or 6-mercaptopurine.
Infliximab, a monoclonal antibody may use in fulminant colitis.
Surgical treatment(Colectomy)
:
Performed for intractable disease, complications of therapy, and fulminant disease
that is unresponsive to medical management.
Crohn Disease (Regional Enteritis, Regional Ileitis, Granulomatous Colitis)
Involves any region of the alimentary tract from the mouth to the anus.
Gastrointestinal involvement in Crohn disease is transmural. The initial presentation
most commonly involves ileum and colon (ileocolitis) but may involve the small
bowel alone in about 30% (70% of these patients have terminal ileitis alone) or colon
alone in 10%-15%.
Upper gastrointestinal involvement (esophagus, stomach, duodenum) is seen in up
to 30% of children.
Clinical Manifestations
Patients with small bowel disease are more likely to have an obstructive pattern
(most commonly with right lower quadrant pain) characterized by fibrostenosis, and
those with colonic disease are more likely to have symptoms resulting from
inflammation (diarrhea, bleeding, cramping).
Systemic signs and symptoms are more common in Crohn disease than in ulcerative
colitis and include:
Fever, malaise, and easy fatigability are common
Growth failure with delayed bone maturation and delayed sexual development may
precede other symptoms by 1 or 2 yr.
Children may present with growth failure as the only manifestation of Crohn disease
Primary or secondary amenorrhea.
Perianal disease is common (tags, fistula, abscess).
Gastric or duodenal involvement may be associated with recurrent vomiting and
epigastric pain.
Enteroenteric or enterocolonic fistulas→ malabsorption
Enterovesical fistulas (between bowel and urinary bladder)→ signs of urinary
infection, or fecaluria.
Perianal fistulas.
Intra-abdominal abscess, Hepatic or splenic abscess, Anorectal abscesses, Perianal
abscess.
Extraintestinal manifestations that are especially associated with Crohn disease
include oral aphthous ulcers, peripheral arthritis, erythema nodosum, digital
clubbing, episcleritis, renal stones (uric acid, oxalate), and gallstones.
Diagnosis
1.History : any combination of abdominal pain (especially right lower quadrant),
diarrhea, vomiting, anorexia, weight loss, growth retardation, and extraintestinal
manifestations.
2. physical examination: Children often appear chronically ill, pale, have weight loss
and malnourished, Digital clubbing.
3. laboratory studies:
*CBP→ anemia, elevated platelet count (>600,000/mm
3
), WBC normal or mildly
elevated.
*Low serum albumin level
*ESR & C-reactive protein → elevated .
*Stool α
1
-antitrypsin level may be elevated
*Anti-Saccharomyces antibodies are identified in 55% of children with Crohn disease
but in only 5% of children with ulcerative colitis.
4. Endoscopic and radiologic findings
*Small bowel follow-through: show aphthous ulceration and thickened, narrowing
of the lumen anywhere in the gastrointestinal tract. Linear ulcers may give a
cobblestone appearance to the mucosal surface.
Other manifestations on radiographic studies that suggest more severe Crohn
disease are fistulas between bowel (enteroenteric or enterocolonic), sinus tracts,
and strictures.
*Ultrasonography and contrast CT: identifying intra-abdominal abscess.
*MRI: localize areas of active bowel disease. It is useful during pregnancy.
*Colonoscopy with biopsy: Findings on colonoscopy include patchy, nonspecific
inflammatory changes, aphthous ulcers, linear ulcers, and strictures. Findings on
biopsy → noncaseating granulomas.
Treatment
1.For mild terminal ileal disease or mild Crohn disease of the colon:
mesalamine (40-60 mg/kg/day).
Sulfasalazine may be effective for mild Crohn colitis but will not be helpful for small
bowel disease.
2. For more extensive or severe small bowel or colonic disease:
Corticosteroids (prednisone, 1-2 mg/kg/day). Tapering can begin by 3-4 wk and
continue over several months.
Steroid enemas → used for distal colon disease.
Children who become refractory to corticosteroid therapy or become dependent on
daily dosing→ Immunomodulators such as azathioprine , 6-mercaptopurine, or
Methotrexate. A beneficial effect of these drugs may be delayed for 3-6 mo after
starting therapy.
Infliximab will be associated with marked symptom improvement in 50-70% of
patients & serve as a bridge until the immunomodulators take effect.
3. To treat perianal disease and perirectal fistula→ Metronidazole (10-20
mg/dL/day), Azathioprine and 6-mercaptopurine.
4. Nutritional therapy: Enteral nutritional approach (elemental or polymeric diet)
administered via a nasogastric or gastrostomy infusion, usually overnight.
High-calorie oral supplements offered to children whose weight gain is suboptimal.
Pubertal delay→ sex steroids.
Short stature→ growth hormone.
Deficits in bone mineral density→ vitamin D therapy.
5. Psychologic counseling & Social support
Surgical therapy
Indictions:
*localized disease of small bowel or colon that is unresponsive to medical treatment
*bowel perforation
*fibrosed stricture with symptomatic partial small bowel obstruction
* intractable bleeding.
Intra-abdominal or liver abscess treated by ultrasonographic or CT-guided catheter
drainage and concomitant intravenous antibiotic treatment.
severely symptomatic perianal fistula may require fistulotomy.