Why Do I Have Bloody Diarrhea, Weight Loss or Severe Abdominal Pain? Could It Be Inflammatory Bowel Disease (IBD)?
Why Do I Have Chronic Diarrhea or Abdominal Pain?
Persistent diarrhea, abdominal pain, weight loss, or blood in the stool should never be ignored. While many digestive symptoms are caused by conditions such as irritable bowel syndrome (IBS), they may also indicate Inflammatory Bowel Disease (IBD)—a group of chronic autoimmune diseases that cause ongoing inflammation of the digestive tract.
Unlike IBS, IBD can damage the intestines and may lead to complications if left untreated. Early diagnosis and appropriate treatment are essential to control inflammation, reduce flare-ups, and improve quality of life.
This evidence-based guide explains the symptoms, causes, diagnosis, treatment options, and long-term management of Crohn’s disease and ulcerative colitis.
What Is Inflammatory Bowel Disease (IBD)?
Inflammatory Bowel Disease (IBD) is the collective term for two chronic inflammatory conditions of the digestive tract:
- Crohn’s disease
- Ulcerative colitis
Both conditions result from an abnormal immune response that causes persistent inflammation in the intestines.
Although symptoms often come and go, IBD is a lifelong condition requiring ongoing medical follow-up.
IBS vs IBD: What’s the Difference?
Although IBS and IBD may cause similar digestive symptoms, they are very different conditions.
| Feature | IBS | IBD (Crohn’s Disease & Ulcerative Colitis) |
|---|---|---|
| Cause | Functional disorder | Chronic inflammatory disease |
| Inflammation | ❌ No | ✅ Yes |
| Intestinal damage | ❌ No | ✅ Yes |
| Blood in stool | Rare | Common during flare-ups |
| Weight loss | Uncommon | Common |
| Fever | No | May occur |
| Anemia | Rare | Common |
| Night-time diarrhea | Uncommon | Common |
| Colonoscopy | Usually normal | Shows inflammation and ulcers |
| Risk of complications | Low | Higher without treatment |
| Risk of bowel cancer | Not increased | Increased in long-standing ulcerative colitis and extensive colonic Crohn’s disease |
Important: If you have blood in your stool, persistent weight loss, fever, or diarrhea that wakes you from sleep, consult your doctor promptly. These symptoms are not typical of IBS and require medical evaluation.
Crohn’s Disease vs Ulcerative Colitis
Although both are forms of IBD, they affect the digestive tract differently.
| Crohn’s Disease | Ulcerative Colitis |
|---|---|
| Can affect any part of the digestive tract | Affects only the colon and rectum |
| Inflammation may occur in patches | Inflammation is continuous |
| Involves the full thickness of the bowel wall | Usually affects only the inner lining of the colon |
| Fistulas and strictures may develop | Toxic megacolon is a rare but serious complication |
Symptoms of IBD
Symptoms vary depending on disease severity and the part of the digestive tract affected.
Common symptoms include:
- Persistent diarrhea
- Blood in the stool
- Abdominal pain
- Urgency to have a bowel movement
- Weight loss
- Fatigue
- Loss of appetite
- Fever during active disease
- Night-time diarrhea
Some people also develop:
- Mouth ulcers
- Joint pain
- Eye inflammation
- Skin rashes
- Iron-deficiency anemia
- Vitamin B12 deficiency (particularly in Crohn’s disease affecting the terminal ileum)
What Causes IBD?
The exact cause remains unknown.
Current evidence suggests that IBD develops because of a combination of:
- Genetic susceptibility
- Immune system dysfunction
- Environmental factors
- Changes in the gut microbiome
- Smoking (particularly in Crohn’s disease)
IBD is not caused by stress, although stress may worsen symptoms during flare-ups.
Who Is at Risk?
Risk factors include:
- Family history of IBD
- Young adulthood (although IBD can occur at any age)
- Smoking (Crohn’s disease)
- Previous intestinal infections
- Certain genetic factors
How Is IBD Diagnosed?
Your doctor may recommend:
- Blood tests
- Stool tests (including fecal calprotectin)
- Colonoscopy with biopsy
- CT scan or MRI
- Capsule endoscopy in selected patients
These tests help distinguish IBD from IBS and other digestive disorders.
When Should You See a Doctor?
Seek medical advice promptly if you develop:
- Blood in the stool.
- Persistent diarrhea lasting more than a few weeks.
- Unexplained weight loss.
- Fever with digestive symptoms.
- Severe abdominal pain.
- Night-time diarrhea.
- Persistent fatigue or anemia.
- A family history of IBD with new digestive symptoms.
Seek emergency medical attention if you develop severe abdominal swelling, persistent vomiting, inability to pass stool or gas, or severe rectal bleeding.
Treatment of Inflammatory Bowel Disease (IBD)
The treatment of inflammatory bowel disease aims to:
- Reduce inflammation.
- Control flare-ups.
- Achieve long-term remission.
- Prevent complications.
- Improve quality of life.
Treatment depends on:
- Whether you have Crohn’s disease or ulcerative colitis.
- Disease severity.
- The part of the digestive tract affected.
- Your response to previous treatments.
Most people require long-term follow-up with a gastroenterologist.
Medications for IBD
Several types of medicines are available.
Aminosalicylates (5-ASA)
Examples include:
- Mesalazine (Mesalamine)
- Sulfasalazine
These medicines reduce inflammation, particularly in ulcerative colitis.
They may be used:
- During flare-ups.
- To help maintain remission.
Corticosteroids
Examples include:
- Prednisolone
- Budesonide
Corticosteroids rapidly reduce inflammation and are often used for moderate to severe flare-ups.
However, because long-term corticosteroid use can cause significant side effects—including osteoporosis, diabetes, weight gain, cataracts, and increased susceptibility to infections—they are not intended for long-term maintenance therapy.
Immunomodulators
Examples include:
- Azathioprine
- Mercaptopurine
- Methotrexate
These medicines help reduce abnormal immune activity and may help maintain remission.
Regular blood tests are usually required to monitor for potential side effects.
Biologic Medicines
Biologics have transformed the treatment of moderate to severe IBD.
Examples include:
- Infliximab
- Adalimumab
- Vedolizumab
- Ustekinumab
- Risankizumab
These medicines target specific components of the immune system to reduce intestinal inflammation.
JAK Inhibitors
Examples include:
- Tofacitinib
- Upadacitinib
These newer oral medicines may be appropriate for selected patients with moderate to severe ulcerative colitis or Crohn’s disease after specialist assessment.
Can Surgery Cure IBD?
Sometimes surgery becomes necessary.
Crohn’s Disease
Surgery may be required to treat:
- Intestinal narrowing (strictures)
- Fistulas
- Abscesses
- Bowel obstruction
However, surgery does not cure Crohn’s disease, and inflammation may recur.
Ulcerative Colitis
In severe cases, removal of the colon (colectomy) can effectively cure the intestinal disease, although it is a major operation with important lifestyle implications.
Diet and Nutrition
There is no single “IBD diet.”
Dietary needs vary depending on whether the disease is active or in remission.
During flare-ups, some people tolerate:
- White rice
- Bananas
- Applesauce
- Potatoes
- Lean chicken
- Fish
- Eggs
- Soup
Better than:
- High-fiber foods
- Nuts
- Seeds
- Popcorn
- Alcohol
- Highly spicy meals
Outside flare-ups, most people benefit from a balanced, varied diet unless specific foods consistently trigger symptoms.
Nutritional Deficiencies
People with IBD are at increased risk of deficiencies because of reduced absorption, inflammation, blood loss, or reduced food intake.
Common deficiencies include:
- Iron
- Vitamin B12
- Folate
- Vitamin D
- Calcium
- Zinc
Blood tests may be recommended periodically to monitor nutritional status.
Can Supplements Help?
Supplements may be useful to correct documented deficiencies or support nutritional status, but they do not replace medical treatment for IBD.
Supplements in IBD at a Glance
| Supplement | Potential Benefit | Evidence | Routine Recommendation? |
|---|---|---|---|
| Iron | Treats iron-deficiency anemia | ⭐⭐⭐⭐⭐ Strong | ✅ Yes, if deficient |
| Vitamin B12 | Prevents deficiency, especially in Crohn’s disease affecting the ileum | ⭐⭐⭐⭐⭐ Strong | ✅ Yes, if deficient |
| Vitamin D | Supports bone and immune health | ⭐⭐⭐⭐ Good | ✅ Correct deficiency |
| Calcium | Bone health, especially with corticosteroids | ⭐⭐⭐⭐ Good | ✅ If intake is inadequate or steroids are used long term |
| Zinc | Supports immune function and intestinal healing | ⭐⭐⭐ Moderate | ✅ If deficient |
| Curcumin | May help maintain remission in mild to moderate ulcerative colitis when used with mesalazine | ⭐⭐⭐ Moderate | ⚠️ Adjunct only |
| Butyrate | Supports intestinal barrier and colon cells | ⭐⭐ Emerging | ⚠️ Adjunct only |
| Probiotics | May benefit selected patients with ulcerative colitis or pouchitis | ⭐⭐⭐ Moderate | ⚠️ Strain-dependent |
| Prebiotics | Support beneficial gut bacteria | ⭐⭐ Emerging | ⚠️ Best introduced gradually, often during remission |
| Omega-3 | General health benefits | ⭐⭐ Limited for IBD remission | ❌ Not routinely for IBD treatment |
Iron
Iron supplementation may be necessary for iron-deficiency anemia, which is common in IBD.
Some people tolerate intravenous iron better than oral iron, particularly during active disease.
Vitamin B12
Vitamin B12 deficiency is particularly common in Crohn’s disease affecting the terminal ileum or after surgical removal of part of the small intestine.
Vitamin D
Low vitamin D levels are common in people with IBD.
Correcting deficiency supports bone health and overall wellbeing.
Calcium
People receiving corticosteroids for prolonged periods may require adequate calcium intake to help maintain bone health.
Omega-3 Fatty Acids
Omega-3 fatty acids have anti-inflammatory properties.
Although early research suggested possible benefits, current evidence does not support routine omega-3 supplementation as a treatment for maintaining remission in Crohn’s disease or ulcerative colitis.
Omega-3 supplements may still be appropriate for cardiovascular health or other indications.
Probiotics
Research suggests that certain probiotic strains may help restore the balance of the gut microbiome and support intestinal health, but their benefits vary depending on the type of inflammatory bowel disease.
Overall, the evidence is strongest for ulcerative colitis and pouchitis, while there is currently little convincing evidence that probiotics are effective for Crohn’s disease. Therefore, probiotics should be considered a complementary therapy rather than a replacement for prescribed medications.
Probiotic Strains Studied in IBD
De Simone Formulation (formerly the original VSL#3®, now available as Visbiome® in some countries) ⭐⭐⭐⭐
This high-potency, eight-strain probiotic is the most extensively studied probiotic formulation in inflammatory bowel disease.
It contains:
- Lactobacillus plantarum
- Lactobacillus paracasei
- Lactobacillus acidophilus
- Lactobacillus delbrueckii subsp. bulgaricus
- Bifidobacterium longum
- Bifidobacterium breve
- Bifidobacterium infantis
- Streptococcus salivarius subsp. thermophilus
Clinical studies suggest that this formulation may help:
- Support remission in mild to moderate ulcerative colitis.
- Reduce the risk of recurrent pouchitis after surgery.
- Improve some digestive symptoms in selected patients.
The evidence is much weaker for Crohn’s disease.
Bifidobacterium longum BB536 ⭐⭐⭐
Some clinical studies suggest that Bifidobacterium longum BB536 may help reduce inflammation and improve symptoms in selected patients with ulcerative colitis, although additional research is needed before routine use can be recommended.
Lactiplantibacillus plantarum 299v (formerly Lactobacillus plantarum 299v) ⭐⭐
This strain has shown promising results in small studies for improving intestinal barrier function and reducing digestive symptoms. Although it may support gut health, evidence in IBD remains limited and it is not considered a standard treatment.
Saccharomyces boulardii CNCM I-745 ⭐⭐
This probiotic yeast is well known for reducing the risk of antibiotic-associated diarrhea, but its role in IBD is less clear.
Small studies have suggested possible benefits in Crohn’s disease, but current evidence is insufficient to recommend routine use specifically for IBD.
Which Probiotics Have the Best Evidence?
| Probiotic | Ulcerative Colitis | Crohn’s Disease | Pouchitis |
|---|---|---|---|
| De Simone Formulation (Visbiome® / original VSL#3 formulation) | ⭐⭐⭐⭐ | ⭐ | ⭐⭐⭐⭐⭐ |
| Escherichia coli Nissle 1917 | ⭐⭐⭐ | ⭐ | Insufficient evidence |
| Bifidobacterium longum BB536 | ⭐⭐ | ⭐ | ⭐⭐ |
| Lactiplantibacillus plantarum 299v | ⭐⭐ | ⭐ | Insufficient evidence |
| Saccharomyces boulardii CNCM I-745 | ⭐⭐ | ⭐⭐ | Insufficient evidence |
💊 Pharmacist’s Tip
When choosing a probiotic, the strain matters more than the number of bacteria (CFUs). Products containing clinically studied strains are more likely to provide benefits than supplements that simply advertise “50 billion bacteria” without identifying the specific strains. If you have IBD, discuss probiotic use with your gastroenterologist, particularly if you are taking immunosuppressive or biologic medications or have severe active disease.
Can Butyrate Supplements Help in IBD?
Butyrate (butyric acid) is a short-chain fatty acid naturally produced by beneficial gut bacteria when they ferment dietary fiber in the colon. It serves as the primary energy source for the cells lining the colon and plays an important role in maintaining the intestinal barrier.
Research suggests that butyrate may:
- Support the integrity of the intestinal lining.
- Help maintain the gut barrier (“leaky gut”).
- Reduce inflammatory signaling in the colon.
- Promote healing of the intestinal lining.
- Support a healthy gut microbiome.
Some small clinical studies have suggested that oral butyrate supplements or butyrate enemas may improve symptoms in selected patients with ulcerative colitis, particularly when used alongside standard medical treatment. However, results have been inconsistent, and larger, high-quality clinical trials are still needed.
For Crohn’s disease, the evidence is currently more limited.
At present, butyrate supplements should be viewed as a supportive therapy rather than a replacement for prescribed IBD medications.
How Can You Increase Butyrate Naturally?
The body produces butyrate when beneficial gut bacteria ferment certain types of dietary fiber.
Foods that may support natural butyrate production include:
- Oats
- Barley
- Legumes
- Cooked and cooled potatoes (rich in resistant starch)
- Cooked and cooled rice
- Green bananas
- Apples
- Onions
- Garlic
- Asparagus
A diverse, fiber-rich diet supports butyrate-producing bacteria, although some people with active IBD may need to modify their fiber intake during flare-ups based on medical advice.
💊 Pharmacist’s Perspective
Interest in butyrate supplements has grown because they target intestinal barrier health, an area receiving increasing attention in digestive research. While butyrate supplements may be a reasonable complementary option for some patients after discussion with their gastroenterologist, they should not replace anti-inflammatory medications or biologic therapies, which remain the foundation of IBD treatment.
Curcumin (Turmeric Extract)
Curcumin, the main active compound in turmeric, has anti-inflammatory and antioxidant properties and has been studied as a complementary treatment for inflammatory bowel disease.
Several clinical studies suggest that curcumin, when used together with mesalazine (5-ASA), may help improve symptoms and maintain remission in people with mild to moderate ulcerative colitis. The evidence for Crohn’s disease is less consistent, and more research is needed.
One challenge is that curcumin is poorly absorbed, so formulations with enhanced bioavailability (such as those combined with phospholipids or piperine) may provide better absorption. However, piperine can interact with some medications, so people taking prescription medicines should consult their healthcare professional before using these products.
Curcumin should be viewed as an adjunct to standard medical treatment, not a substitute for anti-inflammatory medications or biologic therapies.
Zinc
Zinc is an essential mineral involved in immune function, wound healing, and maintaining the integrity of the intestinal lining.
People with inflammatory bowel disease may develop zinc deficiency because of chronic diarrhea, intestinal inflammation, reduced absorption, or inadequate dietary intake.
Correcting zinc deficiency may help support:
- Normal immune function.
- Wound healing.
- Intestinal barrier function.
- Overall nutritional status.
Routine zinc supplementation is not recommended for everyone with IBD, but supplementation may be appropriate when a deficiency has been confirmed or is strongly suspected. Excessive zinc intake can interfere with copper absorption and may cause other side effects, so supplements should be used according to medical advice.
Prebiotics
Prebiotics are types of dietary fiber that nourish beneficial gut bacteria and encourage the production of short-chain fatty acids, including butyrate.
Although prebiotics may support long-term gut health, they can increase bloating, gas, or abdominal discomfort during active IBD flare-ups. For this reason, they are generally introduced gradually and are often better tolerated during periods of remission.
💊 Pharmacist’s Tip
Many supplements promoted for inflammatory bowel disease claim to “heal the gut” or “reduce inflammation.” While some—including vitamin D, iron, vitamin B12, zinc, butyrate, and curcumin—have promising roles in selected patients, none should replace the medications prescribed to control intestinal inflammation. The most effective approach combines evidence-based medical treatment with appropriate nutrition, correction of deficiencies, and carefully selected complementary therapies under the guidance of a healthcare professional.
Stress Management
Stress does not cause IBD, but it may worsen symptoms during flare-ups.
Helpful strategies include:
- Regular exercise (when tolerated)
- Meditation
- Yoga
- Good sleep habits
- Psychological support when needed
Pregnancy and IBD
Most women with well-controlled IBD can have healthy pregnancies.
Disease control before conception is important because active disease increases the risk of pregnancy complications.
Many IBD medications can be continued during pregnancy, but treatment decisions should always be discussed with a gastroenterologist and obstetrician.
Vaccinations
Because some IBD medications suppress the immune system, patients should discuss vaccinations with their healthcare provider.
Routine vaccinations are important, and live vaccines may need to be avoided while taking certain immunosuppressive or biologic medications.
IBD in Children
Inflammatory bowel disease can develop during childhood or adolescence.
Children may experience:
- Persistent diarrhea
- Blood in the stool
- Abdominal pain
- Weight loss
- Poor growth
- Delayed puberty
- Fatigue
- Reduced appetite
Early diagnosis is particularly important because untreated inflammation can affect growth and development.
Children with suspected IBD should always be assessed by a pediatric gastroenterologist.
Treatment often includes nutritional support alongside medications to control inflammation and promote normal growth.
Prevention
There is currently no proven way to prevent IBD.
However, the following may support overall digestive health:
- Avoid smoking, particularly if you have Crohn’s disease.
- Follow prescribed treatment to reduce flare-ups.
- Attend regular follow-up appointments.
- Eat a balanced diet.
- Correct nutritional deficiencies.
- Stay physically active as tolerated.
- Keep vaccinations up to date after discussing them with your healthcare provider.
💊 Pharmacist’s Tip
IBD is a chronic inflammatory disease that requires ongoing medical care. Although vitamins, probiotics, and other supplements may help correct nutritional deficiencies or support overall health, they cannot replace anti-inflammatory medications prescribed to control intestinal inflammation. If you develop persistent diarrhea, blood in the stool, unexplained weight loss, or severe abdominal pain, seek medical assessment rather than self-treating with over-the-counter remedies.
Can IBD be cured?
Crohn’s disease cannot currently be cured, but many people achieve long periods of remission with appropriate treatment. Ulcerative colitis can be cured surgically by removing the colon, although surgery is usually reserved for selected cases.
Is IBD the same as IBS?
No. IBS is a functional bowel disorder without inflammation, whereas IBD is a chronic inflammatory disease that can damage the intestines.
Can stress cause IBD?
No. Stress does not cause IBD, but it may worsen symptoms or trigger flare-ups in some people.
Can people with IBD take probiotics?
Some probiotic strains may be helpful in ulcerative colitis and pouchitis, but they are not a substitute for prescribed medication.
Can children develop IBD?
Yes. Early diagnosis is important because IBD can affect growth, nutrition, and development.
Clinical Disclaimer
This article is intended for educational purposes only and should not replace professional medical advice. Consult your doctor promptly if you develop persistent diarrhea, blood in the stool, unexplained weight loss, fever, severe abdominal pain, or symptoms that do not improve. People with inflammatory bowel disease require ongoing medical supervision and should not stop prescribed medications without consulting their healthcare provider.
Related Articles
- Why Do I Keep Getting Bloating, Constipation or Diarrhea? IBS (Irritable Bowel Syndrome) Explained
- Why Do I Have Diarrhea? Causes, Treatment, Dehydration & When to Worry
- Why Am I Constipated? Causes, Symptoms, Treatment & Fast Relief
- Why Do I Keep Getting Heartburn? GERD (Acid Reflux): Symptoms, Causes & Treatment
- Probiotics: Benefits, Best Strains, Uses, Side Effects & Interactions
- Vitamin D: Benefits, Dosage, Side Effects & Interactions
- Iron: Benefits, Dosage, Side Effects & Interactions
References
- European Crohn’s and Colitis Organisation (ECCO). Guidelines on Crohn’s Disease and Ulcerative Colitis.
- American College of Gastroenterology (ACG). Clinical Guidelines for Crohn’s Disease and Ulcerative Colitis.
- British Society of Gastroenterology (BSG). IBD Clinical Guidelines.
- National Institute for Health and Care Excellence (NICE). Crohn’s Disease and Ulcerative Colitis Guidelines.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Inflammatory Bowel Disease.
- World Gastroenterology Organisation (WGO). Inflammatory Bowel Disease Global Guidelines.