A Boy With Frequent Diarrhea: Differentiating IBS From IBD

Lindsey G. Albenberg, DO; Wenjing Zong, MD


March 18, 2019

Editorial Collaboration

Medscape &

Focused Physical Exam

A normal physical examination does not preclude a diagnosis of IBD.

Plot the child's weight and height on a growth chart

  • Obtain historical points if possible. Weight loss, lack of weight gain, and/or decline in linear growth velocity are red flags. These changes warrant further investigation into nutritional status and may be a sign of IBD. Typically, children with IBS have normal weight gain and growth.

Perform a perianal examination

  • Skin tags in the anal area, particularly if multiple, inflamed, and/or in positions other than 6 or 12 o'clock, may be a sign of IBD. A fistula surrounding the anus with or without drainage or an abscess in the anal area, including tenderness, swelling, erythema, induration, or fluctuance, may be indications of IBD.

Perform a physical exam

  • Several extraintestinal manifestations of IBD can be identified on physical examination, including oral aphthous ulcers, arthritis, erythema nodosum, and uveitis. It is important to recognize that oral ulcers, in particular, are often seen in healthy children.

Next Steps

The patient is referred to the pediatric gastroenterologist for evaluation of diarrhea. When making a referral to a GI specialist to investigate for IBD, it is important that the primary care clinician tell the family what to expect. Make sure that they understand that additional blood and stool tests are useful in detecting indicators of IBD and in ruling out other possible causes of the child's symptoms. To obtain a firm diagnosis of IBD, which is required before starting treatment, a GI specialist will generally need to perform an endoscopy and colonoscopy with biopsies. Imaging studies will also be performed to assess the small bowel.