Do I Have IBS?

By: Pamela Garjian, MD

Irritable bowel syndrome is a functional gastrointestinal disorder that is common and can affect up to 20% of the adult population. It is predominantly seen in women, but also can occur in men. Symptoms might include abdominal pain, bloating, diarrhea, constipation and mucous. In fact there are a specific set of standards called the ROME III criteria that your physician might use to make the diagnosis. It includes abdominal pain at least 3 days per month out of the last 3 previous months, (and these symptoms must have started at least 6 months before). Additionally, a patient must have 2 or more of the following symptoms:

  • Improvement of pain with bowel movements
  • Change in bowel movements
  • Consistency or frequency


As opposed to another disease called inflammatory bowel disease (IBD), IBS is a multitude of GI symptoms where the intestinal tract is not damaged. Other associated IBS symptoms include feeling that a bowel movement is incomplete, passing mucus, predominant diarrhea, predominant constipation, or alternating diarrhea and constipation, bloating, and/or gas.

What causes IBS?                                                                                                                                                                                                                    

The cause of IBS is probably multifactorial. It is believed to include problems with the brain gut signal, motility disorders and contractions and spasms such as hyper or hypo-active gut, hypersensitivity of the intestines especially to stretching of the walls of the intestine, bacterial overgrowth possibly of the small intestine, genetics, food sensitivity, and disordered body chemicals. Some studies suggest that up to 60% of patients with IBS predominant diarrhea have had an infectious gastroenteritis preceding their symptoms. Essentially, IBS is a complicated disorder.

How is the diagnosis made?

The diagnosis of IBS is one of exclusion, which means that the doctor might run some tests to exclude other organic diseases such as gluten intolerance, lactose intolerance, inflammatory bowel disease, (which includes Crohn’s disease and ulcerative colitis), food allergies, sorbitol intolerance, H. pylori, gallbladder disease, ulcer disease, chronic constipation without IBS, eosinophilic enteritis, and infectious colitis. It is important that there are no “alarm symptoms” that might suggest a different diagnosis, such as fever, rectal bleeding, weight loss, anemia or low red blood cell count, family history of colon cancer, family history of celiac disease or inflammatory bowel disease. Tests might include a sigmoidoscopy, colonoscopy, stool studies, blood tests, and breath tests.

How is a treated?

Diet and lifestyle modifications may play a role and may be helpful for some patients. Certain diets have claimed to alleviate symptoms associated with IBS (Such as the FODMAP diet). However, this has caused much controversy because up to two thirds of patients with IBS will respond to dietary changes. Additionally, some foods are unpredictable because of their inconsistency in triggering IBS. Medication such as prescription anti-spasmodic medicines, over-the-counter probiotics, fiber, prescription antibiotics, and mental health therapy may all be helpful.

Diet and nutrition

Diet may play an important role in IBS and a food diary may be helpful and can help determine what triggers your symptoms. Furthermore, it is a possibility that a patient with IBS has an additional digestive problem such as lactose intolerance. A low FODMAP diet has been getting a lot of attention over the last several years and usually restricts gluten, fructose, sorbitol, sucrose, and lactose.   FODMAPs include foods such as wheat, barley, rye, legumes, mango, honey, pears, apples, mushrooms, cauliflower, onions, sugar-free candies, gum, garlic, and lactose. Although this is a very restricted diet, some studies suggest that it may be helpful. Other possible dietary restrictions can include low-fat or PALEO diet.

In summary

IBS is a common complicated constellation of many symptoms that may have several possible causes. Treatment needs to be tailored to the individual patient. Your gastroenterologist with your input, may be able to help you sort out these details. It is important however not to mistake a more serious organic illness as IBS. Furthermore if long-standing IBS symptoms change, then testing may be required to exclude another disease process. Consulting with your gastroenterologist is an important part of the diagnosis and treatment of this condition.