Posted 4/13/2012 5:16 PM (GMT -6)
From the Digestive Diseases Information Clearinghouse: "No specific test for IBS exists, although diagnostic tests may be performed to rule out other problems. These tests may include stool sample testing, blood tests, and x rays. Typically, a doctor will perform a sigmoidoscopy or colonoscopy, which allows the doctor to look inside the colon by inserting a small, flexible tube with a camera on the end of it through the anus. The camera then transfers the images of the colon onto a large screen for the doctor to see better.
If test results are negative, the doctor may diagnose IBS based on symptoms, including how often a person has had abdominal pain or discomfort during the past year, when the pain starts and stops in relation to bowel function, and how bowel frequency and stool consistency have changed. Many doctors refer to a list of specific symptoms that must be present to make a diagnosis of IBS." You can read more in their section on IBS here: http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/#diagnostic
Regarding your urine. If it is very dark at times, try drinking more water. Dark urine is most often caused by dehydration. Did you tell your doctor about your heartburn? He might suggest using over the counter antacids or GERD medication. You probably need to follow up with him given the number of questions you have.