What happens in the intestines
In microscopic colitis, immune cells accumulate in the colon mucosa, interfering with the absorption of water and electrolytes. With the lymphocytic variant, an increased number of lymphocytes is visible between the epithelial cells; with the collagen variant, a thickened strip of collagen is formed under the epithelium. In both cases, water remains in the intestinal lumen, and the stool becomes copious and watery. In this case, the mucous membrane does not ulcerate, there is no bleeding, and the intestinal wall itself is not destroyed - which is why upon examination everything looks fine.
- Accumulation of lymphocytes in the mucosal epithelium
- Thickening of the collagen band in the collagen form
- Impaired absorption of water and salts
- No ulcers or erosions
- Normal appearance on routine bowel examination
Causes and provoking factors
The exact cause is unknown; suggest that the immune system reacts to gut contents in predisposed individuals. Medications play an important and often overlooked role: symptoms may begin with regular use of non-steroidal anti-inflammatory drugs, proton pump inhibitors, some antidepressants and diabetes medications. A significant risk factor is smoking, which also worsens the response to treatment. The disease is often combined with celiac disease, autoimmune thyroiditis and rheumatoid arthritis.
- Age over 50 years and female gender
- Smoking
- Nonsteroidal anti-inflammatory drugs
- Proton pump inhibitors
- Some antidepressants
- Concomitant autoimmune diseases
- Celiac disease
Symptoms
The main symptom is profuse, watery stools, sometimes up to ten or more times a day. The hallmarks are the absence of blood and the presence of nocturnal episodes, which are usually uncharacteristic of irritable bowel syndrome. Sudden and difficult to control urges, including episodes of incontinence, cramping abdominal pain, bloating and fatigue are often disturbing. Moderate weight loss is possible due to dietary restrictions. Symptoms may come and go in waves and last for months or years.
- Watery stools without blood or mucus
- Nocturnal episodes of diarrhea
- Sudden and strong urges
- Cramping pain and bloating
- Fatigue and weakness
- Moderate weight loss
Diagnostics
The main rule: for chronic diarrhea, a colonoscopy is performed with biopsies taken from different parts of the colon, even if the mucous membrane looks healthy. Without a biopsy, the diagnosis is missed. Fecal calprotectin may be slightly elevated or normal, so it does not rule out disease. Be sure to check celiac disease, thyroid function, rule out infections and parasites, and evaluate the relationship with medications. If in doubt, the doctor excludes bacterial overgrowth syndrome and pancreatic insufficiency.
- Colonoscopy with multiple mucosal biopsies
- Histological examination of samples
- Fecal calprotectin
- Coprogram, stool tests for infections and parasites
- Tests for celiac disease
- TSH and complete blood count
Treatment
The first step is to review medications with your doctor and stop possible triggers, as well as quit smoking. For mild symptoms, antidiarrheals and limiting caffeine, alcohol, lactose, and sorbitol-containing products may help. The main drug for active disease is budesonide, a locally acting glucocorticoid with low systemic effect; it is prescribed by the doctor in a course followed by a dose reduction. After discontinuation, relapses are common, then the course is repeated or maintenance therapy is selected. If the course is persistent, other immunosuppressive drugs are considered. Self-medication is unacceptable.
- Cancellation of provoking drugs in consultation with a doctor
- Quitting smoking
- Limit caffeine, alcohol, lactose and sorbitol
- Antidiarrheals for mild cases
- Budesonide course as prescribed by a doctor
- Maintenance therapy for frequent relapses