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. 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 micro-ulcers.
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: 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: 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. For children with growth failure → 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.