Clinical Practice Guideline
Developed for the
Aerospace Medical Association
by their constituent organization
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.
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.
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.
Jacobs, Danny O. Diverticulitis. N Engl J Med 2007; 357: 2057-66.
Sheth, A. et al. Diverticular disease and diverticulitis. Am J Gastroenterol 2008; 103: 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