Irritable Bowel Syndrome: The Importance of the Differential Diagnosis

By Barbara D. Goldberg
Tuesday, November 5, 2013

It has been estimated that irritable bowel syndrome (IBS) affects as much as 10 to 20 percent of the population and women more so than men.1 Symptoms include recurrent episodes of abdominal pain or cramping, bloating, diarrhea and constipation.

While not typically life-threatening, the effects of IBS can be debilitating, lead to frequent absences from the workplace and have a negative impact on a patient’s quality of life. More seriously, IBS — which tends to be overdiagnosed — may mask a more serious condition, such as colon cancer, Crohn’s disease, ulcerative colitis or celiac disease.

Although a recent study reported in the American Journal of Gastroenterology found that IBS does not appear to increase the risk of polyps, colon cancer or inflammatory bowel disease (IBD),2 a patient with a history of IBS may still develop colon cancer, so appropriate screening commensurate with the patient’s risk factors (i.e., older than 50, family history, unexplained weight loss, anemia, bleeding from the GI tract) should be conducted.

Failure to diagnose colon cancer can result in significant liability for a specialist who fails to make the diagnosis, as well as a general practitioner who fails to make an appropriate referral to a specialist. If the colon cancer ultimately proves fatal, the damages awarded may be substantial — particularly if the decedent was married and survived by young children. In such a case, the damages include not only the patient’s pain and suffering but also the pecuniary loss to the patient’s dependents.

It is essential, therefore, to rule out a diagnosis of colon cancer in patients who present with risk factors for malignancy. Conversations emphasizing the importance of recommended tests, as well as the patient’s refusal of any diagnostic procedure, such as a colonoscopy or GI series, should be appropriately documented in the chart.

The same analysis applies to Crohn’s disease, ulcerative colitis and IBD, which can result in significant pain and loss of enjoyment of life.

At the same time, extensive diagnostic testing is not always warranted, and complications from an invasive procedure, such as a colonoscopy, may give rise to a claim for medical malpractice. Fortunately, patients with IBS typically present with a constellation of specific symptoms.3 It has been suggested that using these diagnostic criteria in conjunction with “alarm features” allows physicians to minimize the extent of diagnostic testing necessary to diagnose IBS.4 The Rome II criteria for diagnosis of IBS include the presence of abdominal pain or discomfort for 12 weeks — not necessarily consecutive — in the preceding 12 months and at least two of the following three features regarding symptoms: (1) relieved with defecation; (2) associated with change in frequency of defecation; and/or (3) associated with a change in form or appearance of stool.5 Additional symptoms may include passage of mucus and bloating or distention.6

“Red flag” or “alarm features,” in turn, include unexplained weight loss — which may be associated with malignancy, IBD and celiac disease — as well as persistent diarrhea or severe constipation, which may be associated with an organic disease.7 Other “alarm features” include blood in the stool — which can reflect an infectious process or colon cancer — and fever, which suggests a possible infection or inflammatory disorder.8

Where such features are present, the more serious condition must be ruled out. Additionally, if a patient diagnosed with IBS does not respond to therapy, the diagnosis may be reassessed in three to six weeks and additional evaluations may be performed.9

Careful documentation of discussions with a patient as to why only limited testing is being recommended in the absence of “alarm features” is essential, as this allows the patient to participate in the process and understand the inherent uncertainties.10 This may prove essential to the defense in the event of an adverse outcome and subsequent medical malpractice or lack of informed consent claim.


Barbara D. Goldberg is a Partner at Martin Clearwater & Bell LLP and head of the firm’s Appellate Department. For more information, please visit www.mcblaw.com.