Diarrhea with blood—could this be IBD hiding in plain sight?

Experiencing diarrhea with blood can be unsettling. While many cases of bloody diarrhea stem from infections or common digestive issues, it sometimes signals a deeper problem—namely inflammatory bowel disease (IBD). Recognizing when blood in your stool warrants further investigation can help you get the right treatment sooner rather than later.

What is inflammatory bowel disease (IBD)?

IBD is a chronic condition characterized by inflammation of the gastrointestinal (GI) tract. The two main types are:

• Ulcerative colitis
  • Affects only the colon (large intestine) and rectum
  • Inflammation occurs in a continuous stretch of tissue
• Crohn’s disease
  • Can involve any part of the GI tract from mouth to anus
  • Inflammation often appears in “patches” with healthy tissue in between

(Adapted from Torres J. et al., Lancet 2017)

Common symptoms of IBD

IBD symptoms can overlap with other GI issues, but key features include:

• Persistent diarrhea (often urgent)
• Abdominal cramping or pain
• Visible blood or mucus in stool
• Unexplained weight loss
• Fatigue or low energy
• Anemia (low red blood cell count)

Because these symptoms can come and go in “flares,” it’s easy to dismiss an episode as a passing bug—until it returns.

When to suspect IBD over other causes

While acute infections (e.g., bacterial gastroenteritis) can cause bloody diarrhea, consider IBD if you notice:

• Diarrhea lasting more than two weeks
• Blood in stool on multiple occasions
• Recurring abdominal pain and urgency
• Unintentional weight loss
• Persistent fatigue or weakness

If your episodes recur or don’t resolve with simple measures, seeing a specialist can help clarify the cause.

Other causes of bloody diarrhea

Before assuming IBD, it’s important to rule out other potential culprits:

• Infections (Salmonella, Shigella, E. coli)
• Ischemic colitis (reduced blood flow to the colon)
• Medication-induced colitis (e.g., NSAIDs, antibiotics)
• Hemorrhoids or anal fissures
• Colon polyps or cancer (less common in younger people)

A thorough history, physical exam and tests for pathogens help exclude acute, treatable infections (Foxx-Orenstein AE & McFarland LV, Mayo Clin Proc 2010).

How IBD differs from acute diarrhea

Feature	Acute Infection	IBD
Duration	Days to 1–2 weeks	Months to years, with relapsing flares
Onset	Sudden	Gradual or insidious
Stool characteristics	Often watery, may have blood	Often loose/mucoid, frequently bloody
Associated systemic signs	Fever, chills, malaise	Fatigue, weight loss, extraintestinal signs
Response to antibiotics	Usually improves	No lasting improvement without IBD therapy

Diagnosing IBD

If you and your doctor suspect IBD, the usual diagnostic steps include:

1. Laboratory tests
   • Complete blood count (CBC) to check for anemia
   • Inflammatory markers (CRP, ESR)
   • Stool studies to rule out infections
2. Endoscopy and imaging
   • Colonoscopy with biopsies is the gold standard
   • Flexible sigmoidoscopy or CT/MR enterography in certain cases
3. Histologic evaluation
   • Tissue samples confirm chronic inflammation and rule out other diseases

Early diagnosis is key to preventing complications like strictures, fistulas or malnutrition.

Managing IBD

Treatment aims to induce and maintain remission while minimizing side effects:

• Aminosalicylates (e.g., mesalamine) for mild to moderate ulcerative colitis
• Corticosteroids for short-term control of moderate to severe flares
• Immunomodulators (e.g., azathioprine) to reduce steroid dependence
• Biologic therapies (e.g., anti-TNF agents) for moderate to severe disease
• Nutritional support and supplements to address deficiencies

Working closely with a gastroenterologist helps tailor therapies to your disease pattern.

When to seek urgent care

Certain signs accompanying bloody diarrhea are red flags requiring immediate attention:

• High fever (above 38.5 °C or 101.3 °F)
• Severe abdominal pain or guarding
• Signs of dehydration (dizziness, low urine output)
• Passage of large volumes of blood
• Rapid heart rate or low blood pressure

In these scenarios, a trip to the emergency department can be life-saving.

Next steps and resources

If you’re unsure what’s causing your diarrhea with blood, consider doing a free, online symptom check to guide you on whether you need urgent care or specialist evaluation. While tools like this can offer initial direction, they don’t replace professional medical advice.

Above all, never ignore persistent or severe symptoms. Speak to a doctor promptly about anything that could be life-threatening or serious—especially if blood in your stool is accompanied by other worrisome signs.

---

Talk with your healthcare provider to get a clear diagnosis and the most appropriate treatment plan for your situation.