Microscopic Colitis: Understanding Chronic Diarrhea and Why Budesonide Is the First-Line Treatment

Chronic diarrhea that won’t go away-no blood, no fever, no obvious cause-can be one of the most frustrating health problems. If you’ve been to the doctor multiple times, had normal colonoscopies, and still can’t figure out why you’re running to the bathroom 6 to 10 times a day, you might have microscopic colitis. It’s not flashy. It doesn’t show up on scans. But it’s real. And for thousands of people, especially women over 50, it’s the hidden reason behind their daily misery.

What Exactly Is Microscopic Colitis?

Microscopic colitis is an inflammatory condition of the colon that only shows up under a microscope. Unlike Crohn’s disease or ulcerative colitis, your colon looks perfectly normal during a colonoscopy. That’s why so many people go years without a diagnosis. The inflammation is invisible to the naked eye. You need biopsies-usually taken from multiple spots in the colon-to see the damage.

There are two types: collagenous colitis and lymphocytic colitis. In collagenous colitis, a thick band of collagen-like scar tissue-builds up just beneath the colon lining. In lymphocytic colitis, there’s an overgrowth of white blood cells inside the lining. Both mess with the colon’s ability to absorb water, which is why diarrhea is always watery and never bloody.

It’s not rare. About 5 out of every 100,000 people get diagnosed each year. Rates have more than quadrupled since the 1990s, mostly because doctors are better at testing for it. Women make up 65 to 70% of cases. Most people are diagnosed in their 60s. It’s not caused by diet or stress alone, though those can make symptoms worse.

How Do You Know It’s Microscopic Colitis?

The symptoms are simple, but relentless:

• Chronic watery diarrhea (5-10 bowel movements a day, often for months)
• Abdominal cramping or pain (about half of patients)
• Fecal incontinence (25-35% of people)
• Nocturnal diarrhea (you wake up at night to go)
• Unintentional weight loss (more common in collagenous colitis)

You won’t have fever, vomiting, or blood in stool. That’s why many assume it’s IBS or food poisoning that never cleared up. The average time from first symptom to diagnosis? Eleven months. That’s a year of guessing, avoiding social events, and feeling exhausted.

Diagnosis requires at least four colon biopsies-two from the ascending colon, two from the descending. One biopsy isn’t enough. If your doctor only took one sample and called it normal, you might need a second opinion.

Why Budesonide Is the Gold Standard Treatment

For decades, doctors tried everything: fiber supplements, antidiarrheals, probiotics. Nothing worked reliably. Then came budesonide.

Budesonide is a corticosteroid-but not like prednisone. It’s designed to work locally in the gut. When you swallow it, about 90% of it gets broken down by your liver before it enters your bloodstream. That means it shuts down inflammation in your colon without wrecking your bones, blood sugar, or sleep like traditional steroids do.

Multiple clinical trials show budesonide works. In one study, 84% of collagenous colitis patients went into full remission after 8 weeks of 9mg daily. That’s compared to just 38% on placebo. For lymphocytic colitis, the numbers are similar: 75-85% response rate. Most people feel better within two weeks. Some say it’s like flipping a switch.

The European Microscopic Colitis Group and the American College of Gastroenterology both give budesonide a strong, top-tier recommendation. It’s not just a guess-it’s backed by high-quality evidence from randomized trials.

How It’s Used: Dosing and Duration

The standard starting dose is 9mg per day, taken as a capsule, for 6 to 8 weeks. You don’t need to taper right away. After that, you stop. About 70-80% of people stay symptom-free for months. But here’s the catch: 50-75% come back after stopping.

That’s where maintenance comes in. If your symptoms return, you might need to go back on budesonide-but at a lower dose: 6mg daily, or even 3mg every other day. Some people stay on low-dose budesonide for over a year. It’s not ideal, but it’s safer than going back to prednisone.

Tapering slowly-cutting the dose by 3mg every 2-4 weeks-helps reduce relapse. Jumping off too fast? High chance of symptoms returning. Your doctor should guide this. Don’t self-adjust.

What About Other Treatments?

Budesonide isn’t the only option, but it’s the best. Here’s how others stack up:

• Bismuth subsalicylate (Pepto-Bismol): Works for about 26% of people. Cheap. Safe. But not strong enough for severe cases.
• Mesalamine: Used in ulcerative colitis. Only helps 40-50%. Not reliable for MC.
• Cholestyramine: Good if bile acid malabsorption is part of the problem. Works in 60-70% of those cases. Often combined with budesonide.
• Prednisone: Works as well as budesonide-but side effects are brutal. Weight gain, insomnia, high blood sugar, bone loss. Not worth it.
• Anti-TNF drugs (like infliximab): Expensive ($2,500 per infusion), risky for infection, and only help 20-30%. Reserved for when everything else fails.

The bottom line: if you have moderate to severe microscopic colitis, budesonide is the only drug proven to get you back to normal fast-with minimal side effects.

Side Effects and Safety

Budesonide is safe-for most people. The most common side effects:

• Insomnia (15%)
• Acne (12%)
• Mild mood changes or anxiety (8%)
• Headache or dizziness (rare)

Serious side effects are rare. Because so little of the drug enters your bloodstream, you won’t get adrenal suppression unless you’re on it for more than a year at high doses. Still, if you’re over 50, your doctor should check your bone density and blood sugar before starting.

People with severe liver disease shouldn’t take it. The liver breaks down budesonide. If it’s damaged, too much drug might stay in your system.

Real People, Real Stories

On patient forums, the stories are split. About 68% say budesonide changed their life. One Reddit user wrote: “Went from 10 bathroom trips a day to 2 in 10 days. I hugged my wife for the first time in months.”

But 32% report setbacks. Some relapse after stopping. Others can’t afford it. Generic budesonide costs $150-$250 for an 8-week course. Brand-name Entocort EC? $800-$1,200. Insurance often covers it, but not always.

One patient on PatientsLikeMe said: “Worked great for 6 weeks. Then it stopped. Now I’m on maintenance for two years. I hate that I can’t stop.”

Combination therapy helps some. Budesonide + cholestyramine fixed diarrhea for a woman who’d suffered for three years. It’s worth asking your doctor about.

What’s Next for Treatment?

Research is moving fast. The FDA just gave vedolizumab fast-track status for microscopic colitis. It’s a biologic that targets gut-specific inflammation. Early results show 65% remission at 14 weeks. It’s not approved yet, but it’s coming.

Scientists are also looking at genetics. Early data suggests people with the HLA-DQ2 or HLA-DQ8 genes respond better to budesonide. That could mean personalized treatment in the future: test your genes, then pick your drug.

For now, budesonide remains the standard. It’s not perfect. It doesn’t cure the disease. But it gives people their lives back.

What You Should Do If You Suspect Microscopic Colitis

If you’ve had chronic watery diarrhea for more than 3 months:

1. Ask your doctor for a colonoscopy with multiple biopsies-don’t accept a normal result unless they took at least four samples.
2. If biopsies show microscopic colitis, ask about starting budesonide 9mg daily.
3. Discuss a taper plan before you even start the medication.
4. Get baseline blood work: HbA1c, blood pressure, bone density if you’re over 50.
5. Consider adding cholestyramine if you have bile acid issues.
6. Track your symptoms. Use a diary app. Note how many bowel movements, pain level, sleep quality.

Don’t wait. The longer you go untreated, the more your quality of life erodes. And yes-it’s treatable.