Irritable Bowel Syndrome

Overview of Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is a common condition that affects the intestinal tract and leads to abnormal intestinal contractions. The cause of IBS is not known though there is evidence that it could be due to abnormal intestinal motility, and increased sensitivity of the intestinal nervous system. Some individuals develop IBS after an episode of an intestinal bacterial infection (gastroenteritis) and it is theorized that this leads to changes in one's immune system that affects gut motility and gut sensitivity. It is not contagious, or cancerous. IBS usually begins in the late teens or early 20's. It affects woman more frequently than men with a 2:1 ratio. This is a diagnosis of exclusion and serious causes of intestinal complaints need to be excluded.

Signs & Symptoms

Symptoms vary in affected individuals. The symptoms must have lasted at least three months can include change in frequency of bowel movement, a change in consistency of stool to that of loose or firm stools, and/or combination of firm/loose stools. Intestinal symptoms are frequently relieved by bowel movements.

Other symptoms can include:

  • Abdominal cramps
  • Diarrhea or constipation
  • Abdominal bloating
  • Feeling of incomplete bowel movements
  • Mucous in stools
  • Depression and anxiety


It is diagnosed by taking a careful medical history and by excluding other medical conditions. This includes doing limited lab work to exclude other causes of intestinal problems such as inflammatory bowel disease, gluten sensitivity, lactose intolerance, and intestinal infections. Symptoms that suggest other intestinal causes include blood in the stools, weight loss, fever; and new onset of bowel changes in individuals over 40 years of age. Sometimes a colonoscopy is recommended to identify causes especially in older individuals and/or individuals with worrisome symptoms that can be screened by your medical provider.


  • There is no specific prevention but some foods may make IBS worse such as fatty foods, milk products, chocolate, alcohol, caffeine, and carbonated drinks.
  • For constipation, eating high fiber foods such as fruits, vegetables and whole grains may reduce symptoms.
  • Lactose intolerance, and intolerance to fructose and sorbitol should be excluded.
  • Avoid high gas producing foods such as cabbage, cauliflower, raw onions, garlic, brown beans, and brussel sprouts.


There is no cure for IBS. Most people with IBS are treated by dietary advice and education of the condition. Some individuals can benefit from medications that include:

  • Antispasmodics - for pain and diarrhea
  • Antidiarrheal - such as over the counter loperamide to reduce frequency of loose stools.
  • Fiber - to improve diarrhea or constipation
  • Laxatives - for constipation
  • Antidepressants - for severe pain, anxiety or depression

How We Can Help

  • If you would like to be seen by our medical staff, please contact our Appointment Desk to schedule an appointment.
  • Also, our Advice Nurse service is available at no charge for all UC Davis students to discuss health concerns and the need for medical care.