"The Food Doc" Dr. Scot Michael Lewey, D.O., FACP FAAP FACOP
WHAT IS MASTOCYTIC ENTEROCOLITIS?

Mastocytic enterocolitis (MCE) is a new disorder, still not known to many doctors or patients,
that is often an unrecognized cause of many digestive symptoms, most commonly abdominal
pain and diarrhea. However, it can cause other digestive and non-digestive symptoms and
sometimes it is associated with constipation. It is now known that MCE is a cause of diarrhea
predominant Irritable Bowel Syndrome (IBS). It may be a subtype of IBS or it's own form of
microscopic inflammatory bowel disease (IBD).  

HOW IS MASTOCYTIC ENTEROCOLITIS DIAGNOSED?

Mastocytic enterocolitis is diagnosed by the presence of increased mast cells (more than 20
per high power field under the microscope) in intestinal biopsies. The surface lining of the
intestine in this condition almost always looks completely normal so to detect this disorder
biopsies have to be done by the doctor even when the intestine looks normal. Furthermore,
mast cells cannot be readily seen or counted using the standard stains done on intestinal
biopsies. To be detected, MCE requires that the doctor performing the scope procedure
and/or the pathologist reviewing the biopsy slides have suspicion of the condition or that
they routinely perform special stains (tryptase immunohistochemistry stains) that these cells
stain with and bring them to light so that they are easy to see and count.  

WHAT DOES ENTEROCOLITIS MEAN?

The term enterocolitis comes from the combination of the terms "entero" for small intestine
and colitis. Colitis is comes from colon, shortened to "col", combined with the suffix "-itis"
meaning "inflammation of".  Enteritis, inflammation of the small intestine alone, comes from
"entero" shortened to "enter" combined with "itis".

WHAT EXACTLY ARE MAST CELLS?

Mast cells are a type of immune-infection fighting cell present throughout our body. They are
made in the bone marrow then travel to areas of the body where they serve important
functions such as fighting infections, regulating body functions or nerve signals, and ending
and or recruit other cells to an area of infection or perceived threat. They are able to
perform these tasks because they are rich in various chemicals known as mediators.
Histamine is one chemical mediator that mast cells have a lot of inside them.



HOW DO MAST CELLS FUNCTION AND WHAT ARE THESE CHEMICALS THEY CONTAIN?

Mast cells contain numerous granules or packets of chemicals.  These granules contain a
variety of chemicals that regulate or mediate body reactions. These chemicals in mast cells
therefore are known as chemical mediators. Histamine is one of the main chemical mediators
in mast cells. Histamine is released in great amounts when mast cells are stimulated or
triggered. Other chemicals include interferon, interleukin, leukotrienes, and eosinophilic
chemotactic factor.

WHERE ARE MAST CELLS IN THE BODY?

Mast cells present throughout the body in many tissues including your intestines, brain, skin,
joints, bladder, sexual organs, lungs and even your heart. The superficial intestinal lining or
mucosa of the digestive tract usually contains mast cell in small numbers. The exception is
when you are exposed to parasites, viruses, bacteria, increased stress or you have an
abnormal reaction to certain foods and chemicals or you have developed other chronic
inflammatory diseases of the bowel  such as Crohn's disease, ulcerative colitis, Celiac Sprue
or as we now know, one particular form of Irritable Bowel Syndrome (IBS) called Mastocytic
Enterocolitis.

WHAT HAPPENS WHEN MAST CELLS ARE TRIGGERED IN THE BOWEL OR ARE INCREASED IN
THE INTESTINES?

When mast cells release histamine and other chemicals in the bowels  this irritates or
inflames the bowel making it more permeable or leaky. In essence it creates a leaky gut
syndrome. This can set up a vicious cycle of pain and further gut injury. In the right setting or
genetic predisposition you may develop IBS, colitis, Celiac Sprue, Crohn's disease or a
chronic leaky gut with food intolerance and sensitivity.

WHAT ARE THE SYMPTOMS OF MASTOCYTIC ENTEROCOLITIS OR EXCESS MAST CELLS IN THE
DIGESTIVE TRACT?

The most common symptoms of Mastocytic Enterocolitis or excess mast cells in the digestive
lining are diarrhea, bloating and abdominal pain. However, constipation may occur due to gut
paralysis. When histamine is released, it can cause leaky gut, increased contractions of the
gut or decreased contractions, increased secretions and increased painNausea and
vomiting may also occur commonly especially abruptly without warning and with severe
vomiting. Various other non-digestive symptoms are common with excess mast cells. These
commonly include flushing, headaches, skin rashes, bladder spasms, pelvic pain, muscle and
joint aches and fatigue. In some individuals excess mast cells occur throughout the whole
body and they can have severe, even life threatening symptoms and an increase risk in
cancer. This condition is known as systemic mastocytosis. .

HOW IS MASTOCYTIC ENTEROCOLITIS OR MASTOCYTIC INFLAMMATORY BOWEL DISEASE
(MIBD) DIAGNOSED?

It can only be diagnosed by examination of gastrointestinal tissue obtained by biopsy during
endoscopy. The tissue has to be stained with special stains that bring out these hard to see
or covert immune cells. When you have an endoscopic procedure, the doctor takes samples
of tissue, called biopsies, from the lining of your intestines. The tissue is then sent to a
pathologist who looks at it under the microscope. Since mast cells are very hard to see on
routine biopsies without a special stains they are usually missed unless the doctor knows to
ask for special stains to look for them. These special stains are specific for the enzyme
tryptase that is present in large quantities in mast cells. Mastocytic enterocolitis is
diagnosed when an excess number of mast cells (20 or more per high power field under the
microscope) are present in biopsies of  the gastrointestinal tract lining. If you have had
biopsies and were told they were normal mast cells may have been missed. You should ask
your doctor to request special stains be done if you have symptoms but were told your
biopsies were normal or especially if you were given a diagnosis of IBS.

HOW IS MASTOCYTIC ENTEROCOLITIS OR MASTOCYTIC INFLAMMATORY BOWEL DISEASE
TREATED?

Since mast cells contain lots of histamine antihistamines are usually helpful. Medications that
can reduce or block the release of the histamine released by the mast cells, or
antihistamines, come in two types. The most familiar type of antihistamine to most people are
the type I antihistamines. These include the old fashion sedating antihistamine benadryl or
diphenahydramine and the newer non-sedating type I antihistamines. Type I antihistamines
are typically used for allergy symptoms. Examples include benadryl, which is sedating, and
the non-sedating ones  such as Zyrtec, Allegra, Claritin etc.

There are another class of antihistamines that are familiar drugs to most people but you may
not be aware that they block histamine, but at another receptor site in the body. The type II
antihistamines block histamine particularly in the gut. These include the acid blockers such
as Zantac, Tagamet and Pepcid.

Since mast cells contain chemicals important in inflammation, especially in allergic
conditions, called leukotrienes blockers of leukotrienes may be helpful in mastocytic
enterocolitis. A common leukotriene blocker medication used in asthma and allergies is
Singulair or Montelukast sodium.

The most specific therapy for mastocytic enterocolitis is a medication that stabilizes mast
cells to try to prevent them from releasing their chemical mediators. The only one currently
available is known as cromolyn sodium. It comes in a liquid form that can be taken by mouth
that goes by the brand name Gastrocrom. This drug prevents the release of the various
chemical mediators including histamine from mast cells. In systemic mastocytosis it is
typically prescribed four times a day and the limited published studies on the treatment for
mastocytic enterocolitis utilized this regimen of 200 mg orally four times a day for about 4-6
weeks. Due to the difficulty most patients have taking a four times a day medication and the
expense of gastrocrom I have been prescribing it three times daily.

IS THERE ANYTHING ELSE I CAN DO FOR MASTOCYTIC ENTEROCOLITIS BESIDES MEDICATION?

Along with medication, I recommend you have allergy testing done, work on reducing or
coping better with stress, and consider taking a probiotic supplement. Digestive enzymes
may be of some benefit though this has not been proven.

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