Irritable bowel syndrome (IBS) is a common problem, affecting about 10% to 15% of the population, with women being twice as likely to have the diagnosis (56). Given that its primary symptom is typically crampy chronic abdominal pain, IBS is often in the differential diagnosis for patients with chronic pelvic pain. Stress and certain foods will often trigger the pain, and defecation often will provide some relief from the pain. Other gastrointestinal symptoms include diarrhea and constipation, gastroesophageal reﬂux disease, nausea, bloating, and ﬂatulence. What makes this a more difficult diagnosis is the spectrum of additional symptoms, including dysmenorrhea, dyspareunia, fibromyalgia complaints, urinary symptoms of frequency and urgency, and even sexual dysfunction.
This spectrum of symptoms renders diagnosis difficult and led to a consensus group that created the Rome criteria in 1992, revised in 2005 (57). The resulting Rome III criteria are: recurrent abdominal pain or discomfort for at least 3 days per month for 3 months associated with two or more of the following:
Improvement with defecation
Onset associated with a change in frequency of stool
Onset associated with a change in the appearance of the stool
IBS should be a diagnosis of exclusion with consideration initially given to other causes for the dominant symptom. If that is diarrhea, considerations of lactose intolerance, infectious etiology, malabsorption, or celiac disease should be entertained. Symptoms that result in weight loss, rectal bleeding, anemia, or that are noctural or progressive could indicate something other than IBS unless proven otherwise.
A basic workup might include complete blood count and chemistries. Evaluation of diarrhea, if that is the dominant symptom, should potentially include stool cultures if infectious etiology is suspected or 24-hour stool collection (if osmotic) of secretory diarrhea is suspected. Flexible sigmoidoscopy is not done routinely unless needed to rule out inﬂammatory conditions or malignancy in families with Lynch syndrome. Initiate dietary reviews for lactose intolerance or gluten sensitivity.
Management General management of IBS can be extremely difficult. Often, the first step is to reassure the patient that this is a functional disease and is not related to cancer or malignancy, assuming those were eliminated by history and examination. Many individuals have some underlying concerns that diagnostic testing needs to be performed or that something is being missed. Constant reassurance is an important aspect of management. The patient needs to be an active participant in her care and understand the chronic nature of the disease. A symptom diary for several weeks may show a link between various foods and stressors that may be modifiable. Some individuals are able to link various stressors in their lives to symptoms while others will not have identifiable causes. Common triggers include stress, anxiety, medication (antibiotics, antacids), menstrual cycles, abusive relationships, certain foods (lactose, sorbitol), and travel. Patients should be counseled about dietary interventions, including increasing dietary fiber, decreasing total fat intake, and avoiding foods that trigger symptoms. Stool softeners are recommended for individuals with hard stools, and bulk aiding agents may be helpful for those individuals with constipation. The overuse of laxatives is to be discouraged. Good bowel habits should be discussed. Patients with poor habits should set aside a quiet time every day to attempt defecation. Many individuals get into a habit of ignoring stooling symptoms, leading to further problems with lower gastrointestinal disease.