Transcript Digestive diseases

DIGESTIVE DISEASES
Main Characteristics

The digestive system is composed of:
Peptic Ulcers
Fig. 1.
Fig 1. From: http://digestive.niddk.nih.gov/ddiseases/pubs/hpylori/#5
Fig. 2.
Peptic Ulcers
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Ulcer- sore or lesion that forms in the lining of the
stomach or duodenum where acid & pepsin are
present
Ulcers in the stomach and duodenum are usually
classified as peptic ulcers
Peptic Ulcers
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Ulcers in the stomach
 Gastric
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or stomach ulcers
Ulcers in duodenum
 Duodenal
ulcers
Common Ulcer Symptoms
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Most common: gnawing or burning pain in the abdomen
between the breastbone and navel
Pain often occurs when stomach is empty: between
meals & early morning
May last from a few minutes to a few hours
May be briefly relieved by eating or by taking
antacids
Other less common: nausea & vomiting, loss of
appetite, weight loss, bloating and burping
Other Ulcer Symptoms
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Emergency symptoms:
 Bleeding
 If
in stomach & duodenum
bleeding is heavy, blood will appear in vomit or stool
 Sharp,
 May
sudden, persistent, stomach pain
feel tired & week
Peptic Ulcer Epidemiology
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Before 20th century, peptic ulcers were rare1
About 20 million Americans develop at least one
ulcer during their lifetime
Peptic ulcer disease (PUD) is a common illness that
affects >6 million persons in the United States each
year2
A total of 1,453,892 first-listed PUD
hospitalizations were estimated for 1998–2005
1. Majumdar D, Bebb J, Atherton J. Helicobacter infection and peptic ulcers. Medicine. 2010;30:3.
2. Sandler RS, Everhart JE, Donowitz M, Adams E, Cronin K, Goodman C, The burden of selected digestive diseases in the United States. Gastroenterology. 2002;122:1500–11. DOIPubMed
Peptic Ulcer Epidemiology
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Hospitalization rates were higher for adults ≥ 65
years of age and decreased with decreasing age
group
 Ulcers
are rare in teenagers, more uncommon in
children
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Duodenal ulcers usually first occur between ages of
30-50 yrs. of age
 Also
occur more frequently in men than women
Peptic Ulcer Theories
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For almost a century: believed that ulcers were caused
by lifestyle factors (e.g. stress, diet)
Later, discovered that ulcers were caused by imbalance
between digestive fluids (HCl & pepsin) & stomach’s
ability to defend itself against these
Current: Helicobacter pylori infection as the causative
agent, non-steroidal anti-inflammatory drugs (NSAIDs),
including aspirin and Ibuprofen
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Lifestyle, acid & pepsin production play some role but not
primary cause of most ulcers.
Helicobacter pylori Infections
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Spiral shaped stomach bacterium
Bacteria + acid secretion damages stomach,
duodenal tissue
 Causes
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inflammation (gastritis) & ulcers
H. Pylori can survive in acidic stomach because it
produces urease enzyme
 Urease
generates substances that neutralize the
stomach’s acid
Helicobacter pylori Infection
H. pylori
H. Pylori in
stomach
1. How H. pylori produces ulcers
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Bacteria can penetrate stomach’s protective mucous
lining because of shape & way they move
They produce substances the weaken stomach’s
protective mucus & make the stomach cells more
susceptible to the damage of acid & pepsin
2. How H. pylori produces ulcers
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Bacteria can also attach to stomach cells further
weakening the stomach’s defensive mechanisms &
producing local inflammation
H. pylori can also stimulate the stomach to produce
more acid (not understood why)
3. How H. pylori produces ulcers
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Excess stomach acid & other irritating factors can
cause inflammation of the duodenal bulb
In summary H. pylori induces gastritis through
production of a variety of antigens, virulence
factors, & soluble mediators
The bacterium deregulates, disarms & evades host
immune responses to maintain chronic colonization
of the gastric mucose
H. Pylori infection
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Within weeks of infection with H. pylori, many
develop gastritis (inflammation of stomach lining)
However, most will never experience severe
symptoms or problem related to the infection
Unclear why some people do and others do not
develop H. pylori related symptoms or ulcers
Lifestyle Factors Implicated in Ulcers
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Cigarettes
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Caffeine Foods
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Can stimulate stomach acid secretion & aggravate ulcer
pain
Alcohol Consumption
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Increase ulcer risk, slow rate of ulcer healing
Ulcers more common in people with cirrhosis of liver
Emotional Stress
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No longer thought to be cause of peptic ulcers, but
emotional stress reported to increase ulcer pain
Nonsteroidal anti-inflammatory drugs
(NSAIDs)
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Prescription of NSAID’s (arthritis treatment)
Non-prescription NSAID- aspirin, ibuprofen &
naproxen
Interfere with stomach’s ability to produce mucus &
bicarbonate
Affect blood flow to the stomach & cell repair
Ulcers usually disappear once person stops taking
drug
Diagnosis
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Endoscopic Exams
X-ray examinations
Testing for H. pylori in blood, breath, & tissue
samples
Treatment
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With medicines
H-2 blockers
 Acid pump inhibitors
 Mucosal protective agents
 In H. pylori, these meds used in combination with antibiotics
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Lifestyle changes
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MDs used to advise avoidance of spicy, fatty, or acidic
foods
Surgery
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Usually last result if people don’t respond to meds or
develop complications