--- title: IBS Diagnosis date: 2021-01-29T14:54:00-08:00 author: admin canonical_url: "https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/ibs-diagnosis" section: Resource Library --- [Foodborne Illnesses](/foodborne-illnesses) / [Irritable Bowel Syndrome](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome) / # IBS Diagnosis ### How is IBS diagnosed? Clinicians diagnose IBS by identifying typical symptoms, taking a thorough history, and doing a complete physical examination. Blood and stool tests are often part of the initial evaluation, including blood counts, measuring markers of inflammation in blood and/or stool, and testing for celiac disease in those with diarrhea. Further evaluation is indicated when there are alarm symptoms that indicate organic disease. These include blood in the stools, unexplained weight loss, diarrhea at night, or progressive abdominal pain. A family history of colon cancer or inflammatory bowel disease, onset after age 50, and abnormal laboratory tests also merit further evaluation. In some patients, colonoscopy may be indicated, particularly for anyone 50 or older, or those with a family history of colon cancer or inflammatory bowel disease. ![](https://s3.us-west-2.amazonaws.com/aboutirritablebowelsyndromecom-images/outbreaks/image11_2021-03-03-195852.jpeg) [ Next: IBS Treatment › ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/ibs-treatment) ### More Information [August 13, 2026 ###### Cyclospora and the 2026 Taylor Farms Outbreak: Questions and Answers Marler Clark represents people sickened in the 2026 Cyclospora outbreak and has filed cases naming Taylor Farms entities as defendants. The answers below are written for people trying to understand ... ](https://marlerclark.com/news_events/cyclospora-and-the-2026-taylor-farms-outbreak-questions-and-answers) [August 13, 2026 ###### Salmonella and the 2026 Jalapeño Outbreak: Frequently Asked Questions Marler Clark — The Food Safety Law Firm | Updated August 13, 2026 The questions below come in two parts. The first covers Salmonella generally — what it does, how ... ](https://marlerclark.com/news_events/salmonella-and-the-2026-jalape%C3%B1o-outbreak-frequently-asked-questions) [August 08, 2026 ###### FAQ's: The 2026 Cyclospora Outbreak: Questions and Answers for the Public Updated Saturday, August 8, 2026. Everything below is drawn from the federal and state health department pages linked in the answers, and the numbers move, so check the links before ... ](https://marlerclark.com/news_events/faqs-the-2026-cyclospora-outbreak-questions-and-answers-for-the-public) [July 27, 2026 ###### The Cyclospora Lawsuits Have Begun On July 16, health officials linked shredded lettuce sold at US-based Taco Bell restaurants to the cyclosporiasis outbreak. Within hours, the lawsuits began. At least four lawsuits have been filed ... ](https://marlerclark.com/news_events/the-cyclospora-lawsuits-have-begun) [1. View all ](/news_events/outbreaks?illness=e-coli&year=all) ## All Irritable Bowel Syndrome Resources [###### What is Irritable Bowel Syndrome? ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/what-is-irritable-bowel-syndrome) [###### Causes of IBS ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/causes-of-ibs) [###### Post-Infectious IBS ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/post-infectious-ibs) [###### Dyspepsia and Gastroparesis ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/dyspepsia-gastroparesis) [###### IBS Diagnosis ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/ibs-diagnosis) [###### IBS Treatment ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/ibs-treatment) [###### Irritable Bowel Syndrome References ](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome/irritable-bowel-syndrome-references) ### Other foodborne illnesses [E. coli](https://marlerclark.com/foodborne-illnesses/e-coli) [Salmonella](https://marlerclark.com/foodborne-illnesses/salmonella) [Listeria](https://marlerclark.com/foodborne-illnesses/listeria) [Hepatitis A](https://marlerclark.com/foodborne-illnesses/hepatitis-a) [Reactive Arthritis](https://marlerclark.com/foodborne-illnesses/reactive-arthritis) [Guillain-Barre Syndrome](https://marlerclark.com/foodborne-illnesses/guillain-barre-syndrome) [Norovirus](https://marlerclark.com/foodborne-illnesses/norovirus) [Botulism](https://marlerclark.com/foodborne-illnesses/botulism) [Campylobacter](https://marlerclark.com/foodborne-illnesses/campylobacter) [Shigella](https://marlerclark.com/foodborne-illnesses/shigella) [Cyclospora](https://marlerclark.com/foodborne-illnesses/cyclospora) [Hemolytic Uremic Syndrome](https://marlerclark.com/foodborne-illnesses/hemolytic-uremic-syndrome)