Irritable bowel syndrome is a disorder that is characterized by altered gastrointestinal habits and chronic abdominal discomfort. This condition is reportedly very underdiagnosed, but estimates indicate that 10 to 15% of the United States population may suffer from some form of irritable bowel syndrome.
Many patients may be too embarrassed to discuss their symptoms; thus it is thought that this disease is grossly under reported.
Irritable bowel syndrome is a commonly encountered disorder that impacts millions per year. This disorder is thought to be responsible for almost half of referrals to gastroenterologists.
Irritable Bowel Syndrome: Patient Presentation
The symptoms associated with IBS are variable, however the main symptom that patients usually describe is abdominal discomfort. Patients will classically describe their discomfort as “cramping” and may be mild to severe in nature. Bloating is characteristic of IBS as well.
Patients may also complain of increased flatulence. The hallmark of IBS is a patient with mild to moderate, cramping abdominal pain, that is relieved with defecation. Pain may be worse with emotional stress or with meals.
Patients may suffer from constipation, diarrhea, or a combination of both symptoms. Diarrhea may be frequent, loose, and associated with urgency.
It is important to note that IBS may present similarly to other conditions. IBS should generally be a diagnosis reserved after other more serious disease processes have been ruled out or deemed less likely.
Irritable Bowel Syndrome: The History and Physical Exam
The history and physical exam should focus on ruling out the more concerning pathologies that could result in changes in bowel habits.
As part of a thorough history, patients should be asked about the onset, duration, quality, severity, and timing of their symptoms. Whether the symptoms get worse or better with food or defecation is helpful.
A thorough questioning of the patient’s stool habits is important to rule out more concerning reasons for bowel habit change. Large volume diarrhea, bloody stools, weight loss, or nocturnal diarrhea should warrant more extensive workup for other causes. Extra intestinal symptoms such as joint pain, visual changes, or rash may be suggestive of an auto-immune process.
Other important questions to ask include recent travel, relation to bread products, relation to milk products, and recent antibiotic use and a review of the patient’s medication list. Family history should be documented and should enquire about any history of auto-immune disorders, Crohn’s disease, ulcerative colitis, and colon cancer.
Working up the Patient
The workup for irritable bowel syndrome, as discussed previously, should focus on other causes of constipation or diarrhea. Patients may benefit from obtaining a complete blood count, C-reative protein, or serologic testing for Celiac disease if indicated.
Imaging may be warranted if there is severe constipation or concern for obstruction or malignancy.
As with any condition, it is important to consider alarm symptoms, that should warrant immediate referral or further intervention:
- Patients with onset of symptoms after the age of 50
- Blood in the stool
- Weight loss
- Unidentified iron deficiency anemia should be referred to specialist for evaluation.
It is important to note that nocturnal diarrhea is not consistent with irritable bowel syndrome.
Patients without red flag symptoms or family history may be diagnosed with irritable bowel syndrome without significant laboratory or imaging studies.
ROME IV Criteria
Once an adequate workup has been performed, the diagnosis can be made. Patients with irritable bowel syndrome can be classified via the ROME IV Criteria. This criteria dictates that patients with IBS typically have at least one day of abdominal discomfort per week over a three month period.
It is also associated with relief with defecation, an increase in stool frequency, and a change in stool form or appearance. All of the above points toward a diagnosis of irritable bowel syndrome.
Patients may be further divided into categories such as Irritable Bowel Syndrome with predominantly constipation, predominantly diarrhea, mixed, or unspecified. Of note, women are more likely to be diagnosed with the constipation sub-type.
Treating Irritable Bowel Syndrome
The treatment of irritable bowel syndrome is multifactorial and involves behavioral, physical, dietary, and pharmacologic approaches. It is important to establish a good clinician to patient relationship for continuous, therapeutic care. Patients with IBS may benefit from frequent visits. It is important to make patients aware that IBS is a chronic disease that can wax and wane over time. It is also important to validate the patient’s symptoms.
A standard approach for IBS management is dietary changes. Patients may benefit from a trial of gluten free diet, lactose free diet, depending on their symptoms. A two week trial of avoiding gluten in the diet may be helpful for patient’s symptoms.
Patients may additionally benefit in a diet that is low in total FODMAPS:
Studies have shown that reducing total FODMAPs can be helpful for patients’ symptoms with IBS. It is also important to educate patients about foods that are gas producing, such as beans, legumes, vegetables, and others.
The remainder of IBS management depends on the specific subtype that the patient is experiencing. Patients with predominantly constipation, may benefit from a trial of fiber supplementation, such as psyllium.
Polyethylene glycol is also a reasonable option. This may cause more gas symptoms, but can be helpful for more regular bowel movements.
Physical activity and hydration are additionally two options that may help patients.
Patients that are experiencing predominantly diarrhea, may benefit from a short course of anti-diarrhea medication, or motility agents. Dicylomine or bentyl is a reasonable option for patients with significant cramping and diarrhea.
It is important to note that patients should also focus on diet and behavioral interventions, however anti-spasmodics may be used in the short term setting.
For patients with underlying depression, anxiety, or who fail routine management, anti-depressant medication may be beneficial. Amitriptyline and nortriptyline are reasonable options and may be helpful in the long-term setting. The patient must again be counseled that IBS is a chronic disease that must be managed daily to prevent long term complications.