If you are worried you may have IBS, the first thing to do is visit your physician and explain your symptoms. Now, you should know that there is no definite test to diagnose IBS, so the first thing your doctor will do is probably ask you for your complete medical history. Then you may take a physical exam and different tests that will help them rule out any other condition. This way, they can make sure you have the right treatment for your symptoms.
After the initial tests and checkups, the doctor may use one of the following sets of diagnostic criteria for IBS:
- Manning criteria, which is focused on having incomplete bowel movements and pain that is relieved by passing stool, as well as mucus in the stool and altered stool consistency.
- Rome criteria, including abdominal discomfort and pain that lasts at least one day a week in the last three months, that is also connected to at least two of these options: altered frequency of defecation, altered stool consistency, or pain related to defecation.
- Type of IBS based on your symptoms. It can be divided into three types: diarrhea-predominant, constipation-predominant or mixed.
There are also some other symptoms that may suggest other conditions, that are more serious. Your physician may also check if you have any of these symptoms, and they may indicate you need additional tests, especially if an initial treatment for IBS doesn’t work:
- Nausea or vomiting
- Weight loss
- Persistent diarrhea that may wake you up from your sleep
- Abdominal pain that is not relieved by bowel movement or that happens at night
- Anemia (related to low iron levels)
- Onset of symptoms after age 50
Additional tests may be recommended by your doctor in order to rule out any other causes for your symptoms. These include stool studies, checking your intestine’s ability to take in the nutrients for food, etc.
Imaging tests may also include some of these:
- Colonoscopy, where the doctor examines the entire length of the colon using a small tube
- Flexible sigmoidoscopy, during which, they only examine the lower part of the colon with a lighted tube
- CT scan or X-ray, which may help your doctor to rule out other causes of your symptoms
You may also be asked to do additional lab tests, including:
- Stool tests for parasites and bacteria, or bile acid in case you have chronic diarrhea
- Lactose intolerance tests, because intolerance to sugar found in dairy products may cause diarrhea, gas and abdominal pain. Your doctor may also ask you to remove milk and dairy products from your diet for a few weeks to see if that helps
- Breath test for bacterial overgrowth in your small intestine, which is more common for people who have diabetes or another disease that slow down digestion, or who have had bowel surgery.
- Upper endoscopy, where the doctor inserts a long, flexible tube down your throat and into the tube that connects your stomach with your mouth. They can then use a camera at the end of the tube to inspect your upper digestive tract and take a tissue sample from your small intestine, as well as check for overgrowth of bacteria. This test is common if your doctor suspects celiac disease.
To Sum Up
Since IBS doesn’t have a specific test that helps diagnose it, you may go through many different ones to rule out all other possible options. They may take a while and feel a bit uncomfortable, but they will help your doctor find the best treatment for your symptoms, which is ultimately the best for your health.