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-is one of the most frustrating health problems people face. For many, it’s not just inconvenient; it’s life-shattering. You’re avoiding social events, dreading long drives, waking up at night to rush to the bathroom. And yet, your colon looks perfectly normal on a colonoscopy. That’s the cruel twist of microscopic colitis.

What Exactly Is Microscopic Colitis?

Microscopic colitis isn’t one disease-it’s two. Collagenous colitis and lymphocytic colitis. Both cause the same symptoms: persistent, watery diarrhea, often 5 to 10 times a day. Some people have abdominal cramps, weight loss, or fecal incontinence. Others feel fine except for the constant need to go. The catch? There’s nothing wrong with your colon when your doctor looks inside it. The inflammation is invisible to the naked eye. Only under a microscope, when a biopsy is taken, can you see the problem.

In lymphocytic colitis, the lining of the colon is flooded with too many white blood cells-more than 20 per 100 surface cells. In collagenous colitis, there’s a thick band of collagen-like scar tissue-under the surface lining, at least 10 micrometers thick. These changes don’t show up on scans or during a routine colonoscopy. That’s why diagnosis often takes over a year. Many patients are told they have IBS, told to eat less fiber, or given antidiarrheals that barely help.

It mostly affects older adults, especially women over 60. About 70% of cases are in women. The reason isn’t clear, but hormones, autoimmune triggers, or reactions to medications like NSAIDs, SSRIs, or proton pump inhibitors might play a role. The number of cases has more than quadrupled since the 1990s, mostly because doctors now know to take biopsies when someone has chronic watery diarrhea-even if they look healthy.

Why Budesonide Is the Go-To Treatment

When symptoms are bad enough to disrupt daily life, doctors don’t reach for random remedies. They turn to budesonide. Why? Because it works-and it doesn’t wreck your body like older steroids.

Budesonide is a corticosteroid, but it’s designed to act locally in the gut. When you swallow it, 90% of the drug gets broken down by your liver before it ever enters your bloodstream. That means only about 10-15% circulates systemically. Compare that to prednisone, which floods your whole body. With prednisone, you get insomnia, high blood sugar, mood swings, and bone thinning. With budesonide, side effects are mild: maybe a bit of acne, trouble sleeping, or slight mood changes. Serious side effects are rare.

Multiple studies show budesonide works. In clinical trials, 75% to 85% of people with microscopic colitis go into remission within 6 to 8 weeks. That’s compared to just 25% to 30% on a placebo. For collagenous colitis, one major trial found 84% of patients had complete symptom relief with budesonide, versus only 38% on placebo. Most people feel better within two weeks. One patient on Reddit wrote, “Went from 10 trips a day to 2 in 10 days. I cried when I slept through the night.”

The standard dose is 9 mg once daily for 6 to 8 weeks. That’s it. No long-term use unless you need it. And even then, you don’t stop cold turkey. Doctors taper slowly-drop by 3 mg every two to four weeks-to reduce the chance of symptoms coming back.

What Happens After Treatment?

Here’s the hard truth: budesonide doesn’t cure microscopic colitis. It controls it. About half of the people who stop taking it will have symptoms return within a year. For some, it comes back fast. For others, it’s months or even years.

That’s why 30% to 40% of patients end up on maintenance therapy-lower doses of budesonide, like 6 mg daily, for several months or even years. It’s not ideal, but it’s better than living with daily diarrhea. The European Microscopic Colitis Group recommends maintenance therapy for people who relapse after stopping. Some doctors use it for up to 12 months, especially in older patients who can’t afford to have flare-ups.

But long-term steroid use-even low-dose-raises questions. Are we risking adrenal suppression? Bone loss? Glucose issues? We don’t have perfect data beyond 12 months. Some experts worry we’re treating a chronic condition with a drug not designed for lifelong use. Still, for now, it’s the best tool we have.

Other Options-And Why They Fall Short

There are alternatives, but none match budesonide’s effectiveness.

Bismuth subsalicylate (Pepto-Bismol) helps about 26% of people. It’s cheap and safe, but it’s not enough for moderate to severe cases. Mesalamine (the same drug used for ulcerative colitis) works in 40-50% of patients, but the response is inconsistent. Cholestyramine can help if bile acid malabsorption is part of the problem-about 60-70% respond-but not everyone has that.

Anti-TNF drugs like infliximab? They’re expensive ($2,500-$3,000 per infusion), risky (infections, cancer concerns), and only help 20-30% of people with microscopic colitis. They’re reserved for the rare cases that don’t respond to anything else.

And then there’s cost. Generic budesonide costs $150-$250 for an 8-week course. The branded version, Entocort EC, can run $800-$1,200. Without insurance, that’s a barrier for many. Some patients report having to choose between paying for medication or groceries.

What Patients Really Say

Online forums like Reddit and PatientsLikeMe are full of stories. About 68% of users report major improvement on budesonide. “I got my life back,” one wrote. “I traveled for the first time in three years.”

But 32% had a rougher experience. Some felt worse-insomnia, anxiety, acne. Others got better, then relapsed. One patient wrote: “Worked great for 6 weeks. Then it stopped. Now I’m on maintenance for two years. I don’t know if I’ll ever get off it.”

A few found success combining treatments. One user took budesonide plus cholestyramine and finally got relief after three years of suffering. Another switched from budesonide to a low-FODMAP diet and stayed symptom-free.

The message? There’s no one-size-fits-all. But budesonide gives most people their best shot.

What You Should Know Before Starting

If your doctor prescribes budesonide, ask about these things:

• Do you have a baseline bone density scan? Older adults, especially women, should be checked before starting.
• Are you getting your blood sugar monitored? Even low-dose steroids can raise glucose levels.
• How will you taper? Don’t stop suddenly. Slow reduction lowers relapse risk.
• What if it doesn’t work? Have a backup plan-maybe cholestyramine or a diet change.

Also, don’t assume you’re alone. Microscopic colitis is more common than you think. Incidence has jumped from 1 in 100,000 in 1990 to nearly 5 in 100,000 today. More doctors know to test for it. More patients are being diagnosed. And more are finding relief.

What’s Next for Treatment?

Researchers are looking at new options. Vedolizumab, a drug that targets gut-specific immune cells, showed 65% remission in early trials and got Fast Track status from the FDA in 2023. It’s not approved yet, but it’s coming. Other studies are exploring genetic markers-like HLA-DQ2/8-to predict who responds best to budesonide. That could mean personalized treatment in the future.

For now, budesonide remains the gold standard. It’s not perfect. It’s not a cure. But for most people with microscopic colitis, it’s the difference between living in constant discomfort and living normally again.