There isn’t one specific test that can be used to specifically diagnose irritable bowel syndrome, or IBS, but there are some criteria that can help medical providers determine whether the condition is present. If you’re wondering if you have irritable bowel syndrome and you have some of the more common chronic symptoms, like bloating, cramping, gas, or diarrhea, it’s definitely worth a trip to your doctor’s office for a thorough evaluation and some recommendations to manage the condition. While IBS is challenging to definitively diagnose, it can usually be effectively managed with some dietary changes and behavior modification, and your doctor can help you learn about and implement these changes so your life can return to normal.
The first step in diagnosing IBS is eliminating the likelihood of other, more serious conditions, like inflammatory bowel disease or celiac disease. This is done in an examination that includes a comprehensive medical history, a physical examination, and diagnostic tests of the blood and the stool. In reviewing your symptoms, your doctor will consider your age and whether you have additional symptoms, besides the common gastrointestinal symptoms that characterize IBS, to assess what additional tests might be needed.
If you’re experiencing weight loss, nausea or vomiting, rectal bleeding, fever, or abdominal pain that doesn’t seem related to any outside cause, make sure to tell your doctor. They may recommend a colonoscopy to examine the inside of the colon, or an endoscopy to examine the inside of the esophagus and acquire a tissue sample from the digestive tract. Endoscopies are often recommended if celiac disease is suspected.
If you’re experiencing unusual abdominal pain, a CT scan can be used to take images of the abdomen and look for possible areas of concern. Doctors might also recommend lab tests for patients who report IBS symptoms, like a test for lactose intolerance, which can cause symptoms similar to those of IBS, or they might recommend breath tests to check for bacterial overgrowth in the small intestine. Comprehensive tests of the stool can be performed to find bacterial infection, parasites, or imbalances of gastrointestinal enzymes and acids.
Once more serious conditions have been ruled out, your healthcare provider will measure your symptoms against existing diagnostic criteria to narrow down your diagnosis. One of the standards that is commonly used in diagnosing IBS is the Rome criteria. These criteria include measuring the duration and frequency of discomfort and pain in the belly, which should appear at least once a week over the span of three months to be considered indicative of IBS and should also appear with at least two additional symptoms.
These additional symptoms include pain during defecation, a change in the consistency of the stool, or a change in the frequency of defecation. It is also helpful to divide IBS into one of four types as treatment is being planned. These four types are defined by the symptoms of the condition and are diarrhea-predominant, constipation-predominant, mixed, or unclassified. Depending on the type of IBS symptoms you have, treatment will be tailored to your needs, with the goal of reducing or even eliminating the uncomfortable symptoms that characterize IBS.