What is the difference between IBS and IBD?

While both irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) may cause similar gastrointestinal (GI) symptoms such as abdominal pain and diarrhea, these two conditions are very different.

"When it comes to IBS and IBD, parents can get confused because the conditions sound similar and are sometimes used interchangeably, which is a mistake," says Bhaskar Gurram, M.D., Director of the Southwestern Pediatric IBD program at Children's Health℠ and Associate Professor at UT Southwestern. "The confusion occurs because they have similar symptoms, but the treatments and outcomes are very different."

IBS vs. IBD: What's the difference?

Both IBS and IBD are chronic GI conditions, but they affect the digestive tract in vastly different ways.

IBS does not cause any visible changes or inflammation in the digestive tract. While the cause of IBS is unclear, it is believed to result from both psychological factors and gastrointestinal dysfunction, which lead to bowel hypersensitivity. This hypersensitivity presents as pain, diarrhea and/or constipation.

IBD, which includes Crohn's disease and ulcerative colitis, causes areas of inflammation in the digestive tract. This inflammation can be seen during an endoscopic evaluation by your doctor. Without proper treatment, IBD can progress and lead to various complications that may need surgery.

"If we don't treat these areas of inflammation, your child has an increased risk of surgery, hospitalization or a great need for medications," explains Dr. Gurram.

What causes IBS and IBD?

Causes of IBS

Experts don't yet fully understand the cause of IBS, but they do know that the following factors can contribute to the development of IBS in children:

• Altered gut-brain communication
• Environmental factors including diet changes, changes in gut microbiome
• Genetic changes (polymorphisms) may contribute
• Enteric or gastrointestinal infections (post-infectious IBS)
• Stressful events during childhood

Causes of IBD

Although the exact cause of IBD is unknown, it is thought to arise from an overactivation of the immune system triggered by altered gut microbiome in genetically predisposed individuals.

IBS vs. IBD symptoms

Both IBS and IBD can lead to uncomfortable GI symptoms like abdominal pain and diarrhea. These symptoms can be severe, preventing children from attending school or participating in activities. However, there are some differences between IBS and IBD symptoms.

IBS symptoms include:

• Abdominal pain or cramping
• Constipation and/or diarrhea
• Bloating
• Gas
• Fatigue
• Difficulty sleeping

IBS symptoms may worsen when your child eats certain foods or is under stress.

IBD symptoms include:

• Abdominal pain or cramping
• Diarrhea usually with blood and mucus
• Fever or night sweats
• Fatigue
• Weight loss and/or growth failure
• Anemia

"Noticing blood in the stool is one major symptom difference between the two," says Dr. Gurram. "We don't see rectal bleeding in children with IBS."

IBD can also affect how your child absorbs nutrients. Even if your child eats a well-balanced diet, their body may not take in all the nutrients it needs. Your child may lose weight or grow more slowly than other children their age.

Although IBS and IBD are not as common in younger patients as in adults, these conditions can occur in early adolescence or begin during the teen years.

"We are now diagnosing early-onset IBD in children under age 10 and very early onset IBD in patients under the age of 6," says Dr. Gurram.

Diagnosing IBS vs. IBD in children

Because children with IBS and IBD can have similar symptoms, your child's doctor will need a thorough medical history of your child's symptoms. To determine a diagnosis, your doctor will conduct a physical examination, sometimes including a rectal exam. Your doctor may request blood work and/or stool tests. In many cases, these tests are sufficient to differentiate IBS from IBD.

Based on the findings, your doctor may add additional testing, such as upper and lower endoscopy, a CT scan or MRI scans of the intestines and colon. An upper endoscopy and colonoscopy are required to confirm the diagnosis of IBD before offering treatment.

"Occasionally, it is possible to have both conditions simultaneously," says Dr. Gurram. "One of the theories for this is that the inflammatory process has led the bowel to be hypersensitive to even small stimuli, like certain eating food. So, we have to carefully evaluate if their IBD is not well controlled or if they have IBS on top of IBD."

Treating IBS vs. IBD in children

While there is no simple cure for either condition, symptoms of IBS and IBD can be managed with proper care. IBS is often controlled with cognitive behavioral therapy offered by a psychologist, diet changes, anti-spasmodic medicines, anti-diarrheal medications and neuromodulatory medications. IBD is often treated with anti-inflammatory, immunomodulatory and biologic medications. A pediatric IBD specialist can help determine the best treatment for your child.

Learn more

At the Southwestern Pediatric Inflammatory Bowel Disease Program at Children's Health, we provide personalized treatment, helping over 80% of patients achieve remission from IBD without using long-term corticosteroids. Learn more about our comprehensive IBD program.