Gastroenterology (Gr. 1 Rotations) Flashcards
Organic vs functional disorders (functional dyspepsia, IBS)
Celiac disease
Etiology and epidemiology
Celiac disease is an injury to the mucosa of the small intestine
caused by the ingestion of gluten (a protein component) from
wheat, rye, barley, and related grains. In its severe form, celiac
disease causes malabsorption and malnutrition. The availability
of more sensitive and specific serological testing has revealed
many patients with few or no GI symptoms who have early,
attenuated, or latent disease.
Incidence of celiac disease is
estimated at 1%, but only a small proportion has been diagnosed.
The disease is seen in association with type 1 diabetes, thyroiditis,
Turner syndrome, and trisomy 21.
Celiac disease
Clinical Manifestations
Clinical manifestations
Celiac disease should be considered in any child with…
Extraintenstinal manifestations include…
Symptoms can begin at any age when gluten-containing foods
are given. Diarrhea, abdominal bloating, failure to thrive,
irritability, decreased appetite, and ascites caused by hypoproteinemia
are classic.
Children may be minimally symptomatic
or may be severely malnourished. Constipation is found in a
few patients, probably because of reduced intake. A careful
inspection of the child’s growth curve and evaluation for reduced
subcutaneous fat and abdominal distention are crucial. Celiac
disease should be considered in any child with chronic abdominal
complaints, short stature, poor weight gain, or delayed
puberty.
Extraintestinal manifestations include osteopenia,
arthritis or arthralgias, ataxia, dental enamel defects, elevated
liver enzymes, dermatitis herpetiformis, and erythema nodosum.
Celiac disease
Laboratory and Imaging Studies
Serological markers include…
The biposy specimen shows various degrees of…
Serological markers include IgA antiendomysial antibody and
IgA tissue transglutaminase antibody. Because IgA deficiency
is common in celiac disease, total serum IgA also must be
measured to document the accuracy of these tests. In the absence
of IgA deficiency, either test yields a sensitivity and specificity
of 95%.
An endoscopic small bowel biopsy is essential to
confirm the diagnosis and should be performed while the patient
is still ingesting gluten. The biopsy specimen shows various
degrees of villous atrophy (short or absent villi), mucosal
inflammation, crypt hyperplasia, and increased numbers of
intraepithelial lymphocytes. When there is any question about
response to treatment, a repeat biopsy specimen may be obtained
several months later.
Other laboratory studies should be performed to rule out complications, including complete blood count, calcium, phosphate, vitamin D, iron, total protein and albumin, and liver function tests. Mild elevations of the transaminases are common and should normalize with dietary
therapy.
Celiac diease
Treatment
Treatment consists of…
Starchy foods thar are safe include…
Most paitents respond clinically within a few weeks with…
Histological improvement…
Treatment consists of complete elimination of gluten from the
diet. Consultation with a dietitian experienced in celiac disease
is helpful, as is membership in a celiac disease support group.
Lists of prepared foods that contain hidden gluten are particularly
important for patients to use.
Starchy foods that are safe include rice, soy, tapioca, buckwheat, potatoes, and (pure) oats.
Many resources also are available via the Internet to help families
cope with the large changes in diet that are required.
Most patients respond clinically within a few weeks with weight gain,
improved appetite, and improved sense of well-being.
Histological improvement lags behind clinical response, requiring several months to normalize.
Inflammatory bowel disease
Epidemiology and Etiology
The peak incidence of inflammatory bowel disease (IBD) in
children is in the second decade of life. IBD includes Crohn
disease (CD), which can involve any part of the gut, and
ulcerative colitis (UC), which affects only the colon. The
incidence of IBD is increasing, especially in industrialized
countries, for reasons that are unclear. It is more common in
northern latitudes. IBD is uncommon in tropical and Third
World countries. It is more common in Jewish than in other
ethnic populations. Genetic factors play a role in susceptibility,
with significantly higher risk if there is a family history of IBD.
Having a first-degree relative with IBD increases the risk about
30-fold. Susceptibility has been linked to some human leukocyte
antigen (HLA) subtypes, and linkage analysis has identified
multiple other susceptibility loci on several chromosomes.
Environmental factors (not yet identified) also seem to play a
role because there is often nonconcordance among monozygotic
twins. Dietary and infectious triggers have been proposed but
not yet proven. Smoking increases the risk as well as the severity
of CD and decreases the risk for UC.
Inflammatory bowel disease
Clinical manifestations
Which part does Ulcerative Colitis and Crohn’s Disease involve?
What clinical manifestations results from either one?
What is toxic megacolon and what is it characterized by?
What extraintestinal manifestations may occur in UC?
Small bowel involvement in CD is associated with…
Severe CD with fibrosis may cause…
How does one distinguish CD from UC?
What extraintestinal manifestations may occur in CD?
Clinical manifestations depend on the region of involvement.
UC involves only the colon, whereas CD can include the
entire gut from mouth to anus.
Colitis from either condition
results in diarrhea; blood and mucus in the stool; urgency; and
tenesmus, a sensation of incomplete emptying after defecation.
When colitis is severe, the child often awakens from sleep to
pass stool.
Toxic megacolon is a life-threatening complication
characterized by fever, abdominal distention and pain, massively
dilated colon, anemia, and low serum albumin owing to fecal
protein losses.
Symptoms of colitis always are present in UC and
usually suggest the diagnosis early in its course. Extraintestinal
manifestations of UC occur in a few patients and may include
primary sclerosing cholangitis, arthritis, uveitis, and pyoderma
gangrenosum.
Symptoms can be subtle in CD. Small bowel involvement
in CD is associated with loss of appetite, crampy postprandial
pain, poor growth, delayed puberty, fever, anemia, and lethargy.
Symptoms may be present for some time before the diagnosis
is made.
Severe CD with fibrosis may cause partial or complete
small bowel obstruction.
Perineal abnormalities, including skin
tags and fistulas, are another feature distinguishing CD from
UC.
Other extraintestinal manifestations of CD include arthritis,
erythema nodosum, and uveitis or iritis.
Inflammatory bowel disease
Laboratory & Imaging Studies
Blood tests should include…
What does elevated fecal calprotectin or positive lactoferrin indicate?
Colonoscopic findings in UC include…
Colonoscopic findings in CD
Blood tests should include complete blood count, albumin,
erythrocyte sedimentation rate, and C-reactive protein (Table
129.2).
Anemia and elevated platelet counts are typical. Testing
for abnormal serum antibodies can be helpful in diagnosing
IBD and in discriminating between the colitis of CD and UC.
Serological testing for IBD may be considered but is not recommended
for screening due to poor sensitivity. Elevated fecal
calprotectin or positive lactoferrin testing indicates intestinal
inflammation. These tests have a high negative predictive value
but are not specific to IBD.
In patients with suspected IBD, upper endoscopy and
colonoscopy are recommended.
Colonoscopic findings in UC
include diffuse carpeting of the distal or entire colon with tiny
ulcers and loss of haustral folds. Within the involved segment,
no skip areas are present.
In CD, ulcerations tend to be much
larger and deeper with a linear, branching, or aphthous
appearance; skip areas are usually present. Upper endoscopy
cannot evaluate the jejunum and ileum, but is more sensitive
than contrast studies in identifying proximal CD involvement.
Other methods to detect small bowel involvement include video
capsule endoscopy; upper GI series with small bowel follow
through; computed tomography (CT) scanning, which can detect
small bowel disease as well as abscesses; and MR enterography,
which has the advantage of no radiation and good sensitivity
for finding active bowel disease.
Inflammatory bowel disease
Ulcerative colitis - Treatment
How is UC treated? (With what?)
Route of administration
What should be used when the treatment from question 1 cannot control the disease alone?
What can be used to spare excessive use of [answer to question 3] in difficult cases?
Surgical colectomy with [???] is an option for what?
UC is treated with the aminosalicylate drugs, which deliver
5-aminosalicylic acid (5-ASA) to the distal gut. Because it is
rapidly absorbed, pure 5-ASA (mesalamine) must be specially
packaged in coated capsules or pills or taken as a suppository
to be effective in the colon. Other aminosalicylates (sulfasalazine,
olsalazine, and balsalazide) use 5-ASA covalently linked to a
carrier molecule. Sulfasalazine is the least expensive, but side
effects resulting from its sulfapyridine component are common.
When aminosalicylates alone cannot control the disease, steroid
therapy may be required to induce remission. Whenever possible,
steroids should not be used for long-term therapy. An immunosuppressive
drug, such as 6-mercaptopurine or azathioprine,
is useful to spare excessive steroid use in difficult cases. More
potent immunosuppressives, such as cyclosporine or anti–tumor
necrosis factor (TNF) agents such as infliximab, may be used
as rescue therapy when other treatments fail. Surgical colectomy
with ileoanal anastomosis is an option for unresponsive severe
disease or electively to end chronic symptoms and to reduce
the risk of colon cancer, which is increased in patients with
UC.
Inflammatory bowel disease
Crohn’s disease - Treatment
What drugs are used to induce remission in CD?
To avoid repetitive use of [answer to question 1], what is used often soon after diagnosis?
CD that is difficult to control may be treated with agents that…
Inflammation in CD typically responds less well to aminosalicylates;
- *oral or IV steroids are more important in inducing
remission. **
To avoid the need for repetitive steroid therapy,
immunosuppressive drugs, usually either azathioprine,
6-mercaptopurine, or methotrexate, are often started soon after
diagnosis.
CD that is difficult to control may be treated with
agents that block the action of TNFα such as infliximab or
adalimumab. Other antibodies that inhibit white blood cell
(WBC) migration or action, such as vedolizumab, also show
promise.
Exclusive enteral nutrition can be an effective therapy
for CD. Patients take formula as their sole source of nutrition
for months as a steroid-sparing therapy. Other diets such as
the specific carbohydrate diet continue to be studied as a possible
therapy. As with UC, surgery is sometimes necessary, usually
because of obstructive symptoms, abscess, or severe, unremitting
symptoms. Because surgery is not curative in CD, its use must
be limited, and the length of bowel resection must be
minimized.
Acute abdominal pain
Causes of acute abdominal pain
It is noteworthy that:… (5)
Assessment of the child with acute abdominal pain requires considerable skill. The differential diagnosis of acute abdominal pain in children is extremely wide, encompassing non-specific abdominal pain, surgical causes and medical conditions (Fig. 14.4). In nearly half of the children admitted to hospital, the pain resolves undiagnosed. In young children it is essential not to delay the diagnosis and treatment of acute appendicitis, as progression to perforation can be rapid. It is easy to belittle the clinical signs of abdominal tenderness in young children. Of the surgical causes, appendicitis is by far the most common. The testes, hernial orifices and hip joints must always be checked. It is noteworthy that:
- Lower lobe pneumonia may cause pain referred to the abdomen.
- Primary peritonitis is seen in patients with ascites from nephrotic syndrome or liver disease.
- Diabetic ketoacidosis may cause severe abdominal pain.
- Urinary tract infection, including acute pyelonephritis, is a relatively uncommon cause of acute abdominal pain, but must not be missed. It is important to test a urine sample, in order to identify not only diabetes mellitus but also conditions affecting the liver and urinary tract.
- Pancreatitis may present with acute abdominal pain and serum amylase should be checked.
Acute appendicitis
Signs & Symptoms
Although it may occur at any age, it is very uncommon in…
Clinical features of acute uncomplicated appendicitis
(Symptoms [3] & Signs [3])
In preschool children:… (3)
Acute appendicitis is the most common cause of
abdominal pain in childhood requiring surgical intervention
(Fig. 14.5). Although it may occur at any age,
it is very uncommon in children under 3 years of age.
The clinical features of acute uncomplicated appendicitis are:
Symptoms
- Anorexia
- Vomiting
- Abdominal pain, initially central and colicky (appendicular midgut colic), but then localizing to the right iliac fossa (from localized peritoneal inflammation)
Signs
- Fever
- Abdominal pain aggravated by movement, e.g. on walking, coughing, jumping, bumps on the road during a car journey
- Persistent tenderness with guarding in the right iliac fossa (McBurney’s point). However, with a retrocaecal appendix, localized guarding may be absent, and in a pelvic appendix there may be few abdominal signs.
In preschool children:
- The diagnosis is more difficult, particularly early in the disease.
- Faecoliths are more common and can be seen on a plain abdominal X-ray.
- Perforation may be rapid, as the omentum is less well developed and fails to surround the appendix, and the signs are easy to underestimate at this age.
Acute appendicitis
Diagnosis & Treatment
What treatment is given to those with uncomplicated appendicitis?
What defines a complicated appendicitis?
What should be given if there is generalized guarding consistent with perforation?
Appendicitis is a progressive condition and so repeated
observation and clinical review every few hours are key
to making the correct diagnosis, avoiding delay on the
one hand and unnecessary laparotomy on the other.
No laboratory investigation or imaging is consistently
helpful in making the diagnosis. A neutrophilia is
not always present on a full blood count. White blood
cells or organisms in the urine are not uncommon in
appendicitis as the inflamed appendix may be adjacent
to the ureter or bladder. Although ultrasound is no
substitute for regular clinical review, it may support
the clinical diagnosis (thickened, non-compressible
appendix with increased blood flow), and demonstrate
associated complications such as an abscess, perforation
or an appendix mass, and may exclude other
pathology causing the symptoms. In some centres,
laparoscopy is available to see whether or not the
appendix is inflamed.
Appendicectomy is straightforward in uncomplicated
appendicitis. Complicated appendicitis includes
the presence of an appendix mass, an abscess, or
perforation. If there is generalized guarding consistent
with perforation, fluid resuscitation and intravenous
antibiotics are given prior to laparotomy. If there is a
palpable mass in the right iliac fossa and there are no
signs of generalized peritonitis, it may be reasonable to
elect for conservative management with intravenous
antibiotics, with appendicectomy being performed
after several weeks. If symptoms progress, laparotomy
is indicated.
Non-specific abdominal pain and mesenteric adenitis
What is non-specific abdominal pain?
Non-specific abdominal pain is often accompanied by…
Non-specific abdominal pain is abdominal pain which
resolves in 24–48 hours. The pain is less severe than in
appendicitis, and tenderness in the right iliac fossa is
variable. It is often accompanied by an upper respiratory
tract infection with cervical lymphadenopathy.
In some of these children, the abdominal signs do
not resolve and an appendicectomy is performed.
Mesenteric adenitis is often diagnosed in those
children in whom large mesenteric nodes are seen at
laparoscopy and whose appendix is normal, but there
are doubts whether this condition truly exists as a
diagnostic entity.
Intussusception
General info
What is intussusception?
Intussusception is the most common cause of…
What is the most serious complication and what does it result in?
Intussusception describes the invagination of proximal
bowel into a distal segment. It most commonly
involves ileum passing into the caecum through the
ileocaecal valve (Fig. 14.6a).
Intussusception is the most
common cause of intestinal obstruction in infants after
the neonatal period. Although it may occur at any age,
the peak age of presentation is 3 months – 2 years
of age.
The most serious complication is stretching
and constriction of the mesentery resulting in venous
obstruction, causing engorgement and bleeding
from the bowel mucosa, fluid loss, and subsequently
bowel perforation, peritonitis and gut necrosis. Prompt
diagnosis, immediate fluid resuscitation and urgent
reduction of the intussusception are essential to avoid
complications.
Intussusception
Signs & Symptoms
Presentation is typically with:… (5)
Presentation is typically with:
- Paroxysmal, severe colicky pain with pallor – during episodes of pain, the child becomes pale, especially around the mouth, and draws up the legs. There is recovery between the painful episodes but subsequently the child may become increasingly lethargic.
- May refuse feeds, may vomit, which may become bile stained depending on the site of the intussusception.
- A sausage-shaped mass – often palpable in the abdomen (Fig. 14.6b).
- Passage of a characteristic redcurrant jelly stool comprising blood-stained mucus – this is a characteristic sign but tends to occur later in the illness and may be first seen after a rectal examination.
- Abdominal distension and shock.
Intussusception
Diagnosis & Treatment
An X-ray of the abdomen may show…
Abdominal ultrasound is helpful both to […] and to […]
How is reduction of the intussusception performed?
This procedure [answer to question 3] should only be carried out…
An X-ray of the abdomen may show distended small
bowel and absence of gas in the distal colon or rectum.
Sometimes the outline of the intussusception itself can
be visualized. Abdominal ultrasound is helpful both to
confirm the diagnosis (the so-called target/doughnut
sign) and to check response to treatment.
Unless there
are signs of peritonitis, reduction of the intussusception
by rectal air insufflation is usually attempted by
a radiologist (Fig. 14.6c). This procedure should only
be carried out once the child has been resuscitated
and is under the supervision of a paediatric surgeon in
case the procedure is unsuccessful or bowel perforation
occurs. The success rate of this procedure is about
75%. The remaining 25% require operative reduction
(Fig. 14.6d). Recurrence of the intussusception occurs
in less than 5% but is more frequent after hydrostatic
reduction.
Meckel diverticulum
What is a Meckel diverticulum?
Symptoms?
Lab diagnostic values?
Imaging technique
Treatment
Around 2% of individuals have an ileal remnant of the
vitello-intestinal duct, a Meckel diverticulum, which
contains ectopic gastric mucosa or pancreatic tissue.
Most are asymptomatic but they may present with
severe rectal bleeding, which is classically neither
bright red nor true melaena.
There is usually an acute
reduction in haemoglobin.
Other forms of presentation
include intussusception, volvulus (twisting of the
bowel), or diverticulitis, when inflammation of the
diverticulum mimics appendicitis.
A technetium scan
will demonstrate increased uptake by ectopic gastric
mucosa in 70% of cases (Fig. 14.7).
Treatment is by
surgical resection.
Malrotation
Presentation (clinical manifestations)
During rotation of the small bowel in fetal life, if the
mesentery is not fixed at the duodenojejunal flexure
or in the ileocaecal region, its base is shorter than
normal, and is predisposed to volvulus. Ladd bands
are peritoneal bands that may cross the duodenum,
often anteriorly (Fig. 14.8).
There are two presentations:
- Obstruction
- Obstruction with a compromised blood supply
Obstruction with bilious vomiting is the usual presentation
in the first few days of life but can be seen at a
later age. Any child with dark green vomiting needs an
urgent upper gastrointestinal contrast study to assess
intestinal rotation, unless signs of vascular compromise
are present, when an urgent laparotomy is needed. This
is a surgical emergency as, when a volvulus occurs, the
superior mesenteric arterial blood supply to the small
intestine and proximal large intestine is compromised
and unless it is corrected will lead to infarction of
these areas.
At operation, the volvulus is untwisted, the duodenum
mobilized, and the bowel placed in the nonrotated
position with the duodenojejunal flexure on
the right and the caecum and appendix on the left.
The malrotation is not ‘corrected’, but the mesentery
broadened. The appendix is generally removed to avoid
diagnostic confusion should the child subsequently
have symptoms suggestive of appendicitis.
Warning signs for underlying illness in abdominal pain
Warning signs in Acute abdominal pain (4)
Warning signs in Chronic abdominal pain (8)
Warning signs - Acute abdominal pain
In people with acute abdominal pain, certain symptoms and characteristics are cause for concern. They include
- Severe pain
- Signs of shock (for example, a rapid heart rate, low blood pressure, sweating, and confusion)
- Signs of peritonitis (for example, constant pain that doubles the person over and/or pain that worsens with gentle touching or with bumping the bed)
- Swelling of the abdomen
Warning signs - Chronic abdominal pain
The following symptoms are cause for concern:
- Fever
- Loss of appetite and weight
- Pain that awakens the person during the night
- Blood in vomit, stool, or urine
- Severe or frequent vomiting or diarrhea
- Jaundice (yellowing of the skin and whites of the eyes)
- Swelling of the abdomen and/or legs
- Difficulty swallowing
