Strength of recommendations (A, B, C, D, I) and quality of evidence (good, fair, poor) are defined at the end of "Major Recommendations field."
Subjective Assessment
- Review of past or present symptoms. Alarm symptoms which could suggest an alternative diagnosis of cancer, inflammatory bowel disease (IBS), or infection include:
- Recurrent fever, weight loss, history of blood in stools, chronic severe diarrhea
- Complete family history. A family history of colon cancer is considered an alarm factor; inquire specifically about family history of IBS and celiac disease.
- Psychosocial history, as this may have an important role in the patient's experience of the disease and its outcome
- Consider screening for depression
- Social history including recent travel to areas with parasitic diseases.
- A diagnosis is based on symptoms consistent with the Rome II Diagnostic Criteria
At least 12 weeks, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain that has 2 of 3 features:
- Relieved with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form (appearance) of stool
Symptoms that cumulatively support the diagnosis of IBS:
- Abnormal stool frequency (for research purposes, "abnormal" may be defined as greater than three bowel movements per day and less than three bowel movements per week)
- Abnormal stool form (lumpy/hard or loose/watery stool)
- Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation)
- Passage of mucus
- Bloating or feeling of abdominal distension
The diagnosis of a functional bowel disorder always presumes the absence of a structural or biochemical explanation for the symptoms.
Physical Exam
A complete physical exam should be performed. Included in the exam are vital signs, abdominal exam, pelvic and bimanual exams (if applicable), and rectal exam. A diagnosis of IBS will be supported by negative physical examination findings. Any abnormal findings suggest an alternative diagnosis and should be followed by more extensive evaluation.
Management
Management of IBS is based upon the severity and nature of symptoms, the degree of functional impairment, and any psychosocial factors affecting the disease course. The following pharmacologic treatment recommendations are for patients with moderate to severe symptoms who have not had effective symptom control with dietary, herbal and other recommended pharmacologic agents (anticholinergic, antidiarrheal, 5-HT3, 5-HT4 and other agents including antibiotics, probiotics and complementary therapies).
Antidepressant Treatment of Pain-predominant IBS
- Tricyclic antidepressants (TCAs) (Recommendation B, Quality Fair)
- Amitriptyline
- Desipramine
- Nortriptyline
- Imipramine
- Doxepin
Tricyclic antidepressants in low doses should be considered for patients with pain-predominant IBS or for any patient with moderate to severe symptoms. Secondary amine TCAs (nortriptyline, desipramine) are better tolerated by many patients than parent tertiary amines (amitriptyline, imipramine, doxepin) because of fewer anticholinergic, sedating antihistaminic and alpha-adrenergic adverse effects. Two meta-analyses demonstrated that low-dose tricyclic antidepressants improved pain, global symptoms, and diarrhea. However a systematic review did not support these findings.
- Selective serotonin reuptake inhibitors (SSRIs) (Recommendation I, Quality Poor)
- Citalopram
- Escitalopram oxalate
- Fluoxetine
- Sertraline
- Paroxitene
A pilot open-label study suggested that paroxetine is effective in reducing pain and other IBS symptoms. A literature search revealed only one randomized controlled trial (RCT) examining the use of an SSRI (paroxetine) for treatment of IBS. This trial did suggest an improvement in overall well-being in both depressed and non-depressed individuals with IBS. Given the limited evidence, their use is not recommended as routine or first-line therapy except in patients who also have co-morbid depression.
Psychological Treatments
Psychological treatments should be explored in the patient with moderate-severe symptoms, whose symptoms are associated with stressors, or have associated symptoms of anxiety or depression. The primary care provider should educate the patient and family of the importance of involving mental health professionals in a holistic plan of care. There is convincing evidence that psychosocial factors do not cause the disease, but rather contribute to the predisposition, and continuation of IBS symptoms.
The use of hypnotherapy and cognitive-behavioral therapy (CBT) has proven effective in reducing diarrhea and abdominal pain but has not had significant improvement in constipation-predominant symptoms. It should be noted that any patient with moderate-severe IBS related symptoms could show symptom improvement with these listed therapies, regardless of history of anxiety or depression. Patients should be educated that a referral to a mental health professional is not a diagnosis of a psychological disorder. These therapies have proven effectiveness in all groups of patients, regardless of psychological disposition.
- Hypnotherapy (Recommendation B, Quality Fair)
Most widely studied and used psychological therapy for diarrhea and pain-predominant symptoms. Improvements have been seen in all symptom measures, quality of life and overall well-being. Of the controlled, randomized studies in the last five years, all studies noted improvement with "gut-directed hypnotherapy" versus placebo in reducing diarrhea-predominant and pain-predominant symptoms. Twenty years after hypnotherapy was introduced as an effective treatment for IBS, the mechanisms behind the results are still unclear.
- Cognitive-Behavioral Therapy (Recommendation B, Quality Fair)
Studies on CBT in patients with moderate to severe symptoms show improvement in total somatic symptoms, abdominal pain and bowel dysfunction up to 15 months post therapy. Few studies on the effects of CBT have been conducted in the last five years but evidence from earlier studies show significant improvement with CBT versus symptom monitoring or medical therapy alone. Due to the generally high placebo response rate with functional bowel disorders and the well established psychopathology in IBS, updated high quality studies are needed. Based on the expansive literature from the past twenty years on the use of CBT in bowel disorders, this therapy would be recommended as adjunctive therapy in patients with moderate to severe IBS symptoms who have not responded to medical treatment alone.
Definitions:
Strength of Recommendations (based on U.S. Preventive Services Task Force [USPSTF] ratings)
A. The USPSTF strongly recommends that clinicians provide the service to eligible patients. The USPSTF found good evidence that the service improves important health outcomes and concludes that benefits substantially outweigh harms.
B. The USPSTF recommends that clinicians provide this service to eligible patients. The USPSTF found at least fair evidence that the service improves important health outcomes and concludes that benefits outweigh harms.
C. The USPSTF makes no recommendation for or against routine provision of the service. The USPSTF found at least fair evidence that the service can improve health outcomes but concludes that the balance of benefits and harms is too close to justify a general recommendation.
D. The USPSTF recommends against routinely providing the service to asymptomatic patients. The USPSTF found at least fair evidence that the service is ineffective or that harms outweigh benefits.
I. The USPSTF concludes that the evidence is insufficient to recommend for or against routinely providing the service. Evidence that the service is effective is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined.
Quality of Evidence (based on USPSTF rating)
Good: Evidence includes consistent results from well-designed, well-conducted studies in representative populations that directly assess effects on health outcomes.
Fair: Evidence is sufficient to determine effects on health outcomes, but the strength of the evidence is limited by the number, quality, or consistency of the individual studies, generalizability to routine practice, or indirect nature of the evidence on health outcomes.
Poor: Evidence is insufficient to assess the effects on health outcomes because of limited number or power of studies, important flaws in their design or conduct, gaps in the chain of evidence, or lack of information on important health outcomes.