Clinical Practice Guideline
for
DIVERTICULAR DISEASE
Developed for the
Aerospace
Medical Association
by their constituent organization
American
Society of Aerospace Medicine Specialists
Overview: Diverticular
disease is nearly exclusive to western developed countries. The disease pattern occurs mostly in the
left side of the colon and more than 90% of patients have sigmoid and
descending colon involvement. The
descending, transverse, and ascending portions of the colon are involved in
decreasing order of frequency.
Diverticulosis is rare in undeveloped nations and Asian nations, and if
present, it tends to be a right side predominant disease. Historically, population-based studies show
that diverticular disease has less than a 5% incidence in persons less than 40
years old but the incidence increases rapidly thereafter. Approximately 60% of the general population
develops disease by the age of 80. More
recent studies indicate an increasing prevalence of diverticular disease,
especially in patients under the age of 50.
In addition to low dietary fiber intake, elevated BMI and physical
inactivity have been linked to diverticulitis.
The pathogenesis of diverticular
disease requires defects in the colonic wall caused by increased intraluminal
pressure. This is commonly seen in
western diets that are low in fiber and high in fat. This translates to less bulky stools and
higher intraluminal pressures. There are
two types of diverticula. The most
prevalent are the pseudodiverticula that occur in the sigmoid colon. The prefix pseudo- indicates that they are
not complete herniations of the bowel wall, but rather small protrusions of the
colonic mucosa through openings in the circular muscle layer where the nutrient
blood vessels penetrate the colon wall.
Right sided lesions are true diverticula and much less common.
Diverticulosis is asymptomatic in 80%
of individuals. The remaining 20% can be
divided into two categories: symptomatic
diverticulosis and diverticulitis.
Symptomatic diverticulosis is characterized by episodic pain, altered
bowel habits and a lack of inflammation.
Barium studies may outline the diverticula and reveal an underlying
motility disorder. Symptomatic
diverticulosis may mimic irritable bowel syndrome as well as diverticulitis, so
must be differentiated from other causes of rectal bleeding such as
carcinoma. Colonoscopy is recommended to
rule out neoplastic disease. Recommended
medical treatment includes a high-fiber diet consisting of wheat bran and/or
commercial bulking agents. Analgesics
should be avoided but, if necessary, non-opioid medications are preferred as
morphine could increase intracolonic pressure.
Diverticulitis typically consists
of nausea, abdominal pain, left lower quadrant tenderness with mass, fever, leukocytosis,
and characteristic radiological signs.
Plain abdominal films can identify free air in the abdomen indicative of
perforation. A CT scan with oral and
intravenous contrast is the preferred imaging modality for confirming the
diagnosis. Treatment is based on the
overall health of the patient and the severity of the disease. Stable, uncomplicated patients who tolerate
clear liquids can be treated as outpatients on oral antibiotics. Older patients, those with comorbid
conditions, and anyone unable to tolerate oral fluids should be hospitalized
with IV antibiotics and fluids. Those
with complications such as perforation, abscess formation, fistulization,
sepsis or partial obstruction should be hospitalized for
medical and/or surgical treatment. About 10% of hospitalized patients require surgical treatment.
After the first episode of acute
diverticulitis, approximately 25% of medically treated cases will experience a
recurrence. With each additional
recurrence, the risk of further recurrence and complications increases. In addition to a high fiber diet, physicians
have stressed the avoidance of nuts, seeds and popcorn to reduce the risk of
recurrent disease. Recent studies have
refuted this notion as a cause of diverticular complications, and these dietary
restrictions should no longer be recommended.
Historically, surgical resection of the affected colon was recommended
after the second uncomplicated episode of acute diverticulitis in those over 50
and after the first episode in those under 50.
This was based on studies showing younger patients with more virulent
disease and a greater overall risk of recurrence due to a longer lifespan. However, new data has questioned these
assumptions and the decision to perform an elective colectomy should be
determined based on each patient’s own set of circumstances and treatment
preference. Such patients should be
counseled on the risks and benefits of accepting or declining elective
hemi-colectomy for diverticular disease as several studies have shown that up
to 25% of patients experienced persistent symptoms after elective surgery.
For patients with complicated
diverticulitis requiring hospitalization, as well as patients seeking
prophylactic colectomies, several surgical options are available. Percutaneous drainage of abscesses can
obviate the need for open colectomy in the acute setting. For those requiring colostomy, laparoscopic
colon resection has been shown to be as safe and effective, with less complications
and shorter hospital stays. The need for
staged procedures with initial colostomies is also being questioned, with
primary anastamosis now viewed as a safe and acceptable option in some cases.
Aeromedical Concerns: There is a
minimal risk of in-flight physical incapacitation. Altered bowel habits, episodic pain, nausea,
and flatulence could be a distraction and affect crew availability, both for
those with symptomatic diverticulosis and those experiencing complications
after partial colectomy. Once resolved
and stable, returning the pilot to flying duties should not present a hazard to
flying safety, the individual’s health, or mission completion.
Medical Work-up: The
aviator needs a complete history of the problem to include all consultants
seen, medications used and procedures (colonoscopy results are critical), if
any. Consultation results from a
gastroenterologist or surgeon are also useful as is a list of all medications
used to treat the condition.
Aeromedical Disposition:
Air Force: Diverticular
disease is disqualifying for all classes of flying in the US Air Force. Before waiver consideration, aviators
should have complete resolution of symptoms and be taking no medications
incompatible with flying.
Army: It is
estimated that 20% of people with diverticular disease have a slight risk of
in-flight incapacitation secondary to the development of severe colic or
massive diverticular hemorrhage.
Completely asymptomatic diverticulosis without complication is not
considered disqualifying and does not require a waiver. Once symptoms occur, the disease is one of
frequent recurrence and therefore symptomatic diverticular disease does require
evaluation and waiver.
Navy: Waivers can be considered for aircrew with
diverticulae provided symptoms are minimal and that medication is not required.
Surgical intervention may be required to control symptoms, but colectomy for
incidentally noted asymptomatic diverticulae should not be undertaken.
Civilian: Civil airmen are required to report to the FAA any
medically disqualifying illness. An
acute diverticular episode is disqualifying.
Whether this episode results in surgery or medical treatment, the civil
airman is allowed to gain medical certification after they are stabilized and
no longer having symptoms. In the case
of a surgical resection, a 3 month observation period is generally
required. Airmen who have had a
resection of the colon and are left with a colostomy have been allowed to
fly. Since diverticulosis is a common
cause of rectal bleeding, if the hemoglobin falls to less than 10gms the airman
is not granted medical certification.
The use of antispasmodic medications or Lomotil (diphenoxylate) is not
acceptable in civil aviation.
Waiver Experience:
Air Force: Query of AIMWTS
showed 52 cases of diverticulitis. Of
the 52 cases, none were disqualified for diverticulitis. However, three were disqualified for
unrelated medical conditions. There were
no cases of symptomatic diverticulosis or any disqualifications related to
symptoms after surgical treatment for diverticulitis.
Army: The Aeromedical Epidemiological Data
Repository (AEDR) catalogs all Army flight physicals since 1960. There have been approximately 160,000
individual aircrew entered in this database.
During this period of time, there were only eight aeromedical summaries
submitted and all resulted in a granted waiver.
Navy: Not available at this time.
Civilian: The FAA does not have a specific pathology
code for this condition.
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References:
Jacobs,
Danny O. Diverticulitis. N Engl J Med 2007;
357: 2057-66.
Sheth, A. et al. Diverticular disease and
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1550-1556.
Salzman, Holly, Lillie,
Dustin. Diverticular disease: diagnosis
and treatment. Am Fam
Physician 2005;72:1229-34, 1241-2.
Jeyarajah,
S. et al. Diverticular
disease increases and effects younger ages:
an epidemiological study of 10-year trends. International Journal of Colorectal Disease,
Vol. 23, No. 6, pp. 619-627(9), June 2008.
Rosemar A, Angerås U and Rosengren A.. Body mass index
and diverticular disease: A 28-year
follow-up study in men. Diseases of the
Colon & Rectum, Vol. 51, No. 4, pp 450-55(6), April 2008.
Gearhart,
Susan L. Diverticular
disease and common anorectal disorders. In Fauci, A., et al, editors. Harrison’s Principles of
Internal Medicine. 17th ed. United States of America: The McGraw-Hill Companies, Inc; 2008.
Strate,
L. et al. Nut, corn and popcorn consumption and the incidence of diverticular
disease. JAMA. 2008; 300(8):
907-914.
Egger, B. et al. Persistent symptoms after
elective sigmoid resection for diverticulitis. Diseases of the Colon &
Rectum, Vol. 51, No. 7, pp.1044-1048(5), July 2008.
Janes,
S., et al. Elective surgery after acute diverticulitis. British Journal of Surgery, Vol. 92, No. 2,
pp. 133-142(10), February 2005.
Gonzalez,
R. et al. Laparoscopic
vs. open resection for the treatment of diverticular disease. Surgical Endoscopy, Vol. 18, No. 2, pp.
276-280(5), February 2004.
DeHart,
RL. Selected medical
and surgical conditions of aeromedical concern. In: DeHart RL, Davis JR, editors. Fundamentals of Aerospace Medicine. 3rd
ed. Philadelphia, Pennsylvania; Lippincott Williams & Wilkins; 2002, p.
447.
Rayman,
RB. Clinical Aviation Medicine, 4th
Ed. New York, NY; Professional Publishing Group, Ltd; 2006, p. 19.
Prepared
by Drs Chris Hudson and Dan Van Syoc
Date: September 26, 2010