Dear Doctors: Almost a year after a bout of the stomach flu, I am still having abdominal discomfort. A stool sample test came back normal, but my doctor says I should go see a GI specialist. He thinks the stomach flu gave me IBS. Is that possible? How should I approach getting a diagnosis?
Dear Reader: It's not unusual for digestive symptoms to continue for several weeks after contracting the stomach flu. While the original infection has run its course, the digestive system may need more time to recover. This can affect how food moves through the digestive tract and lead to bloating, nausea and abdominal discomfort. That said, your ongoing digestive distress suggests something else may be going on.
It sounds as though your doctor suspects you may have developed a condition known as post-infectious irritable bowel syndrome. It can arise after an episode of gastroenteritis and cause digestive symptoms to persist long after an initial infection is gone. Post-infectious IBS is widespread and is believed to occur in up to 10% of people who develop a GI infection caused by bacteria, a virus or a parasite.
For those who are not familiar, irritable bowel syndrome, or IBS, is a chronic condition that affects the intestines. Symptoms vary from person to person and can range from mild to severe. People with IBS often experience stomach cramping, localized tenderness, intestinal gas and bloating. Diarrhea or constipation are common, and some people experience both.
The exact causes of IBS are not yet understood. Researchers suspect a glitch in the gut-brain connection plays a key role. Food intolerances, stress, abnormal behavior by the muscles that move food through the GI tract and changes in intestinal permeability may also contribute.
Post-infectious IBS shares many of the same symptoms as IBS -- and as with IBS, the causes are not clear. One theory suggests the initial case of gastroenteritis disrupts the gut microbiome. This can lead to chronic low-grade inflammation and changes in intestinal permeability. Risk factors for the condition include being over 60 and being a woman. People who do not vomit during a case of stomach flu and those whose diarrhea lasts longer than average also appear to be at increased risk.
Although a normal stool sample is reassuring, it would not rule out post-infectious IBS. As your doctor has suggested, that requires further evaluation, often by a gastroenterologist. At this time, there is no single test that can deliver a definitive diagnosis of post-infectious IBS. Although blood tests have been developed that may identify certain biomarkers of the condition, this remains a diagnosis of exclusion. That's a fancy way of saying it is a process of elimination. A doctor will take a medical history, obtain detailed information about your symptoms and may order additional tests to rule out other conditions, such as celiac disease.
Based on your letter, post-infectious IBS is a possibility worth exploring. If your symptoms fit that diagnosis, a gastroenterologist can craft a treatment plan to help you manage this chronic condition.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
