Gastro

Question 1

Please explain the role of the sympathetic nervous system in the
gastrointestinal tract.

Answer 1

Sympathetic fibres are distributed along the entire length of the gut; the
stimulation or inhibition of these plays a role in many aspects of gut
motility. Increased sympathetic stimulation produces the well-known
anxiety symptoms, for example before exams when increased stimulation
produces diarrhoea.

Question 2

What is the difference between a submandibular salivary gland swelling
and swelling of a salivary lymph node?

Answer 2

The salivary lymph glands are part of the superficial lymphatic drainage
of the neck; enlargement occurs in infection and in malignant disease.
The submandibular gland is swollen if there is blockage of the duct or if
a tumour is present. It can also be affected by the mumps virus, although
parotid involvement is more common.

Question 3

How does Barrett’s oesophagus develop?

Answer 3

Barrett’s oesophagus is defined as areas of columnar epithelium with
intestinal metaplasia extending upwards in the lower oesophagus
replacing the normal squamous epithelium. It is due to chronic gastrooesophageal
reflux.

Question 4

Is it recommended to treat asymptomatic endoscopically diagnosed
reflux oesophagitis with acid suppression and/or antireflux
measures?

Answer 4

No, it is not recommended to treat asymptomatic reflux oesophagitis.
However, many gastroenterologists do treat it in the hope that long-term
complications (e.g. stricture, Barrett’s and cancer) can be averted.

Question 5

Is it recommended to give a young patient, diagnosed endoscopically to
have mild reflux oesophagitis, life-long proton pump inhibitors (PPIs) to
prevent the development of Barrett’s oesophagitis?

Answer 5

No, there is no indication to give long-term PPIs in patients with
mild reflux oesophagitis; there is no evidence that this prevents the
development of Barrett’s.

Question 6

Is it safe to give a patient with reflux oesophagitis who is on proton
pump inhibitors (PPIs) for treatment of acid suppression, aspirin in
antiplatelet doses (75–325 mg per day)?

Answer 6

Yes, it is safe to give aspirin to a patient already on a PPI, which is – of
course – cytoprotective

Question 7

Does a combination of magnesium and aluminium hydroxide salts,
taken as antacid for reflux oesophagitis, have serious long-term adverse
effects?

Answer 7

No, there are no serious long-term adverse effects. Usually, however, in
patients who require long-term treatment, an H2-receptor antagonist or a
proton pump inhibitor is used.

Question 8

In the treatment of reflux oesophagitis with a proton pump inhibitor
(PPI), should the PPI be life long or given for 4–8 weeks, as mentioned by
the drug manufacturers?

Answer 8

Patients with reflux oesophagitis usually have a low lower oesophageal
sphincter pressure, so that reflux is a permanent event. After stopping PPIs, the symptoms return and life-long therapy may be necessary. Some
would regard this as an indication for surgery.

Question 9

Would a patient who suffers with reflux oesophagitis as a result of a
hiatus hernia, and who is not responsive to proton pump inhibitors
(PPIs), benefit from a highly selective vagotomy?

Answer 9

No. A highly selective vagotomy will only do the same as the PPIs, that
is, reduce the acid output. Try increasing the dose of the PPI to twice
daily.

Question 10

1. What are the causes of belching and what appropriate drug can be
   used?
2. What are the effects of smoking on the gastrointestinal tract and what
   is its role in peptic ulcer disease?

Answer 10

1. Belching is due to swallowing air. It is often picked up as a habit and
   it is not usually associated with pathology. Occasionally, patients
   who have upper gastrointestinal symptoms, such as heartburn
   or abdominal discomfort, swallow air in an attempt to ease their
   symptoms, and end up belching. Treatment can be difficult; no drugs
   are effective.
2. Smoking impairs the healing of peptic ulcer disease and also makes
   gastro-oesophageal reflux worse. It is also associated with relapse in
   patients with Crohn’s disease (but not in ulcerative colitis) therefore
   all patients with Crohn’s should be encouraged to stop smoking

Question 11

Dear authors, why are gastric ulcers more common along the lesser
curve, near the pylorus of the stomach?

Answer 11

There is no definitive reason why gastric ulcers are more common on the
lesser curve. They are usually just distal to the transitional zone between
the body (acid-secreting mucosa) and antrum (non-acid-secreting mucosa).
Reflux of bile and other duodenal contents into the stomach is thought
to play a role.

Question 12

What is the best time of day to administer omeprazole, and why?

Answer 12

Either morning or evening. It has a prolonged action so that the effect
lasts over 24 hours.

Question 13

Is it safe to use the drugs omeprazole and ranitidine during pregnancy?

Answer 13

Neither drug is recommended in pregnancy, but ranitidine is
probably safe. No drug should be used in pregnancy unless
absolutely essential

Question 14

Are non-steroidal anti-inflammatory drugs harmful to the stomach when
taken parenterally, for example by intravenous or intramuscular routes?

Answer 14

Yes; the inhibition of gastric mucosal cyclo-oxygenase (COX) activity is a
systemic effect.

Question 15

Is it safe to give a patient with a past history of bleeding peptic ulcer
aspirin in an antiplatelet dose of 75–325mg?

Answer 15

A patient with a bleeding peptic ulcer, which is usually due to
Helicobacter pylori, should have eradication therapy. In the case of a
bleeding ulcer, eradication must be checked with a 13C urea breath test or
a stool antigen test. When eradication has been shown to be successful, it is safe to use low-dose aspirin. (Note: patients with and without a history
of ulcers can bleed even with low-dose aspirin.)

Question 16

Is sulpiride effective in the treatment of a peptic ulcer or gastrooesophageal
reflux disease (GORD)?

Answer 16

Sulpiride is not used. It does have an antimuscarinic action, which would
reduce acid production, but in GORD this is offset by a reduction in
lower oesophageal sphincter tone. It is therefore not useful in peptic ulcer
or GORD.

Question 17

Is clopidogrel gentle on the stomach?

Answer 17

Clopidogrel does cause dyspepsia and abdominal pain, and it can lead to
gastrointestinal bleeding. So, is it ‘gentle’? The answer must be ‘No’.

Question 18

Is there a drug interaction between non-steroidal anti-inflammatory
drugs (NSAIDs) and proton pump inhibitors (PPIs)?

Answer 18

There is no drug interaction. Indeed, PPIs are used as mucosal
cytoprotective agents in patients on NSAIDs.

Question 19

Do antacids enhance mucosal resistance in the gastric mucosa? If so,
please indicate the mechanism

Answer 19

If, by antacids, you mean aluminium hydroxide or magnesium
trisilicate the answer is ‘Yes’, but only in very large doses. They work
by neutralizing acid, which in turn makes the mucosa more resistant to
damage. A proton pump inhibitor is more practical

Question 20

Is there a drug interaction between antacids and H2-receptor blockers?

Answer 20

No, but there is little point in using both except for immediate symptom
relief, e.g. with an alginate containing antacid in gastro-oesophageal
reflux disease (GORD).

Question 21

Does the combination of aluminium and magnesium hydroxide, given
as an antacid, decrease the absorption of omeprazole if these are
co-administered to help relieve heartburn quickly?

Answer 21

Omeprazole is formulated as enteric-coated granules and is absorbed in
the small intestine. Antacids therefore have no effect on its absorption.

Question 22

Should proton pump inhibitors be used with caution in patients with
renal impairment?

Answer 22

No.

Question 23

Has cisapride been withdrawn from the market because of the danger of
ventricular fibrillation?

Answer 23

Yes, it increases the Q-Tc interval.

Question 24

In peptic ulcer disease:
1. What are the indications for an upper gastrointestinal endoscopy?
2. As this is an invasive procedure, is an oesophagogastroduodenoscopy
(OGD) or barium meal X-ray preferable?

Answer 24

1. Endoscopy is used in:
   ● Gastric ulcer: for diagnosis and to take biopsies to exclude
   malignancy; it is also used for follow-up of gastric ulcers.
   ● Duodenal ulcer: for diagnosis, although in young patients with
   Helicobacter pylori antibodies and typical history endoscopy is not
   necessary
2. Good double-contrast barium meals are comparable to endoscopy but
   as biopsies cannot be taken (e.g. for H. pylori and malignancy), their
   use is becoming less frequent

Question 25

Is telithromycin as, or more, effective than clarithromycin in the
treatment of Helicobacter pylori? If so, what is the recommended dosage
and how long should treatment be continued?

Answer 25

Telithromycin is a newly introduced macrolide and should be effective
in H. pylori eradication regimens, 800 mg 2 daily. However, you are
always better to stick to the tried and tested – in this case the macrolide
clarithromycin – until the evidence changes.

Question 26

What is the difference between the management of a gastric and of a
duodenal ulcer?

Answer 26

Most duodenal ulcers and 80% of gastric ulcers are due to Helicobacter
pylori infection. Eradication therapy of the organism is the same. It
is usual to check that a gastric ulcer has healed (thereby excluding a
malignant ulcer) by doing repeat gastroscopy; this is not necessary for
duodenal ulcers

Question 27

How does omeprazole suppress Helicobacter pylori?

Answer 27

In vitro, omeprazole inhibits the growth of H. pylori below pH 7.
Clinically, it is thought that omeprazole enhances the local immune
response by increasing intragastric pH. It also reduces the washout of
antibiotics from the mucosa and lowers the inhibitory concentrations of
pH-sensitive antibiotics.

Question 28

Does omeprazole cause rebound hyperacidity? Does this also apply to
H2-blockers?

Answer 28

Rebound increased acid secretion lasting about 2 months occurs after
40 mg a day of omeprazole for 2 days. Yes, rebound hyperacidity also
occurs after withdrawing histamine H2-receptor antagonists

Question 29

You state that the postsynaptic neurotransmitter that
inhibits the relaxation of lower oesophageal sphincter (LOS) is nitric
oxide (NO). I have understood NO to promote relaxation of LOS by
acting on the non-adrenergic, non-cholinergic (NANC) inhibitory
neurones, which inhibits the action of cholinergic excitatory neurones.
Could you please explain this paradox?

Answer 29

The LOS is tonically closed at rest. This resting tone is maintained
by both myogenic properties and active tonic neural excitation. The
reduction in tone and reduction of the LOS that occurs with swallowing
is under the control of cholinergic and NANC neurones. As you say,
NO acts on the NANC inhibitory neurones, which inhibit the excitatory
cholinergic neurones, thus reducing acetylcholine release.

Question 30

It is stated that nitric oxide (NO) inhibits the relaxation of the lower
oesophageal sphincter (LOS) and that sildenafil is given for treating
achalasia. As far as I know, sildenafil acts to increase the guanine
monophosphate (GMP), just as NO uses the same mechanism to relax the
LOS. Could you explain this paradox?

Answer 30

In achalasia there is a selective loss of the inhibitory neurones in
the myenteric plexus. This leads to excitation of the smooth muscle
at the LOS by mediators such as acetylcholine. Sildenafil increases
NO production. It is the NO-containing neurones that are particularly
affected in achalasia so that relaxation of the sphincter is impaired

Question 31

In Kumar and Clark Clinical Medicine you mention that auscultation
is not important in cases of gastrointestinal disorders, but Harrison’s
Principles of Internal Medicine gives this as being of equal importance
because succussion splash and bowel sounds can help in presumptive
diagnosis. Succussion splash indicates gastric obstruction (e.g.
gastroparesis) and likewise bowel sounds can help determine the status
of developing ileus. Would you agree that this is therefore a diagnostic
tool?

Answer 31

In practice, outside the emergency room or postoperatively (looking for
ileus), bowel sounds are not helpful. A succussion splash can indicate
gastric obstruction but is seldom helpful in practice.

Question 32

Is it hazardous to give aspirin in the antiplatelet doses (75–325 mg/day)
to a patient with a past history of haematemesis proved to be from a
peptic ulcer?

Answer 32

Any patient who has bled from a peptic ulcer – and who is therefore
presumably Helicobacter pylori (HP) positive – should have eradication
therapy. Successful eradication of HP following a bleed must be checked
with either an HP breath test or a stool test. After eradication, the same
risks of aspirin therapy apply as to the normal population

Question 33

How can upper gastrointestinal (GI) bleeding be distinguished from
lower GI bleeding by using faecal analysis?

Answer 33

There are no reliable ways of distinguishing lower from upper
gastrointestinal bleeding by faecal analysis. Obviously bright red blood
suggests lower GI bleeding – except when blood loss is huge, when
blood loss from higher up can be bright red blood. Altered blood, e.g. a
melaena stool, is from lesions proximal to the caecum.

Question 34

In upper gastrointestinal bleeding, without knowing the cause or
source of bleeding, why do we give proton pump inhibitors (PPIs,
e.g. omeprazole)? What is the role of these, if the source of bleeding is
not peptic or duodenal ulcer?

Answer 34

Approximately 50% of cases of GI bleeding are from peptic ulcer disease,
and a PPI (e.g. omeprazole) reduces the rate of recurrent bleeding and
the need for surgery. In many patients it is initially unclear where the
bleeding is coming from, so PPIs tend to be given to everybody even
though they have never been shown to be of value in, for example,
variceal bleeding

Question 35

Why is the incidence of coeliac disease increasing in many countries?

Answer 35

The answer is that we have better serological screening tests, e.g.
tissue transglutaminase and endomysial antibodies, which are now
being used extensively. The general awareness of coeliac disease has
also increased.

Question 36

Are small amounts of gluten harmful to a patient with coeliac disease?

Answer 36

Theoretically, yes! However, even a gluten-free diet has very tiny
amounts of gluten and probably these small amounts are not overtly
harmful in most patients. A few patients might be very sensitive

Question 37

I refer to the treatment of complications related to diverticular disease.
Under ‘bleeding’ you mention that ‘Persistent bleeding can often be
arrested by undertaking an “instant” barium enema, which acts to plug
the offending diverticulum’. When I mentioned this to my consultant he
said he had never heard of this. Could you clarify how this would work
and where I could obtain more information?

Answer 37

This is anecdotal data and is probably incorrect; often the bleeding stops
spontaneously. We have decided to remove this anecdotal piece of advice
from future editions.

Question 38

In children with abdominal pain and fever, does a white cell count help
establish a diagnosis of appendicitis?

Answer 38

Between 70 and 90% of patients with appendicitis have a raised white
cell count 15000. This has a sensitivity of 20–60%, with a specificity
of 85–100% in children with appendicitis. Imaging (e.g. ultrasound and
computed tomography) should now be used to make a diagnosis of
appendicitis.

Question 39

I have always been taught that ulcerative colitis only affects the
large bowel with some associated proctitis. I read in your chapter on
gastrointestinal disease that it can cause mouth ulcers and am now
confused.

Answer 39

You have been correctly taught. Ulcerative colitis (UC) only affects the
large bowel, i.e. the colon and rectum, with a small number of patients
having some inflammation of the very distal part of the ileum (called
backwash ileitis). This distinguishes UC from Crohn’s disease, which
affects anywhere from the mouth to the anus, most commonly the small
and large bowel. Both diseases are, however, associated with ‘nonspecific’
mouth ulcers, which also occur in a number of gastrointestinal
diseases (e.g. coeliac disease) and other conditions (e.g. Behçet’s disease).

Question 40

In pseudomembranous colitis, what is the first treatment of choice,
metronidazole or vancomycin?

Answer 40

Metronidazole is the first choice, largely due to the cost of oral vancomycin.

Question 41

Is Crohn’s disease considered as an autoimmune disease. If it is, are there
other predisposing factors to it other than genetics? If it is not, what is its
nature?

Answer 41

Crohn’s disease is not usually considered to be an autoimmune disease,
although the immune system is very involved in the pathological
process. We do not know the exact cause of Crohn’s disease but it is felt
by most that some aetiological agent (perhaps a bacterium?) stimulates
the immune system to over-respond in a genetically susceptible person.
CARD 15 gene mutations contribute to disease susceptibility.

Question 42

Why does carcinoma of the ascending colon cause more anaemia than
obstruction, and carcinoma of the descending colon more obstruction
features and less anaemia?

Answer 42

Carcinoma of the caecum and ascending colon tend to bleed and cause
anaemia but not obstruction because of the large size and ‘give’ in the
right side of the colon. The reverse is true of the descending colon; a
carcinoma is more likely to obstruct the smaller, more rigid left colon

Question 43

Can you explain why a patient with colorectal carcinoma might present
with diarrhoea and abdominal pain?

Answer 43

Very often, the symptoms are not related and the colorectal cancer is
found incidentally when a patient is investigated for pain or diarrhoea
Right-sided colonic lesions do not usually produce gut symptoms.
Lesions in the sigmoid do, probably by partial obstruction

Question 44

What causes the blood to be altered in the presentation of melaena: is it
intestinal juice?

Answer 44

No; it is bacteria.

Question 45

What is the differential diagnosis of multiple rectal ulcers in an 18-year old
female?

Answer 45

Multiple rectal ulcers are common in inflammatory bowel disease. They
also occur in infective proctitis (e.g. due to amoebae) or in sexually
transmitted infections (e.g. herpes viral infections). Rectal spread occurs
in gonococcal infection and can produce ulcers. The answer is to take
samples for cultures and biopsies for histological diagnosis.

Question 46

What is the best surgical technique in a chronic (2–3 years) painful anal
fissure that is located sagittally posteriorly?

Answer 46

A lateral internal sphincterotomy is the best surgical procedure.

Question 47

Can I make a diagnosis of irritable bowel syndrome (IBS) in a 40-year-old
female patient without doing gastrointestinal investigations?

Answer 47

You must first make sure that there are no ‘alarm’ symptoms (Box 6.1).
Take a very careful history because most patients of this age with IBS will
have a preceding history of IBS. Simple blood tests and a follow-up of the
patient are also very helpful in the diagnosis.

Question 48

What is the cause of abdominal bloating, which is often a symptom in
patients with irritable bowel syndrome (IBS)?

Answer 48

This is difficult to answer! We agree this is a very common symptom. It is
not due to air/wind, which most patients think.

Question 49

1. Where is the Traub’s area situated anatomically?
2. What does it mean if it is dull on percussion?
3. What is the proper way to percuss this area?

Answer 49

Traub’s space is an area of resonance overlying the gas bubble in the left
lateral hemithorax. Its size and localization depend on the contents and
position of the stomach. Percuss with the patient on his or her right side.

Question 50

In general, it is claimed that only water and some salts are absorbed
in the large gut, whereas the small gut is practically free of bacteria
(which are present only in the large gut). In a patient on broad-spectrum
antibiotics, bleeding can occur as a result of vitamin K deficiency. If the
flora synthesizing vitamin K is disturbed, how can vitamin deficiency
occur when the large gut is not supposed to absorb? How can this be due
to a change in bacterial flora?

Answer 50

Small amounts of menaquinones (a form of vitamin K), which are
synthesized by bacteria, are absorbed in the colon.

Question 51

Why does colonic cancer more commonly occur on the left rather than
the right side of the colon?

Answer 51

It is true that 55–60% of colonic tumours occur on the left side; this
figure includes rectal cancers (20%). There is no convincing reason for
this; suggestions include faecal stasis on the left side and mucosal
deficiencies at a cellular level.

Question 52

How much more likely are patients with reflux oesophagitis to develop
cancer of the oesophagus than normal people and does aggressive
treatment with H2-blockers or proton pump inhibitors nullify this
increased risk?

Answer 52

Patients with weekly reflux symptoms are nearly eight times more likely
to develop adenocarcinoma compared with those without symptoms.
The greater the frequency, severity and duration of reflux symptoms,
the greater the risk (Lagergren et al. 1999). The risk is unaffected by drug
therapy as far as we know, but proton pump inhibitors (PPIs) are usually
given

Question 53

In Crohn’s disease localized to the ileum there are long-term side effects
and pros and cons of drug therapy. Is ileal resection a better option
(if Crohn’s disease is localized to the ileum) than long-term medicine
therapy which risks complicating lymphoma of the ileum?

Answer 53

Not necessarily better as, of course, Crohn’s disease often recurs after
surgery. It is, however, a useful treatment particularly if localized pain in
the right iliac fossa (due to partial obstruction) is a prominent symptom

Question 54

Alarm symptoms: indications for upper gastrointestinal

endoscopy

Answer 54

● Dysphagia
● Weight loss
● Protracted vomiting
● Anorexia
● Haematemesis or malaena