Researchers reveal prevalence of persistent symptoms in patients with microscopic colitis

It's a hidden cause of diarrhea, and the development of the disease is poorly understood. Multiple factors work against the diagnosis of microscopic colitis, an inflammatory digestive disease, because the symptom distress compared to patients with other causes of chronic diarrhea remains unknown.

Now, a new study published in journal Gastro Hep Advances shows that patients may be unsure of a diagnosis based on their colonoscopy results, patients may not be prescribed the proper medications, and many patients may remain symptomatic one year after colonoscopy.

The study, led by corresponding author Walker Redd, MD, a clinical outcomes and epidemiology fellow in the Division of Gastroenterology and Hepatology at the UNC School of Medicine, involved a cohort of patients from April 1, 2015 to December 22, 2020 enrolled at UNC Hospitals in Chapel Hill, NC. Patients participating in a follow-up survey included 74 with biopsy-confirmed microscopic colitis and 162 patients experiencing other causes of chronic diarrhea (diarrhea controls) after colonoscopy at a one-year follow-up.

"We thought it was important to better understand the burden of symptoms among those patients with microscopic colitis within the context of all patients undergoing colonoscopy to evaluate diarrhea," Redd said.

Survey results in regard to a microscopic colitis diagnosis showed 10% were unaware of the diagnosis. Among the controls, 7% reported a diagnosis of microscopic colitis despite no clinical documentation. Researchers also found that 15% of controls either thought they had microscopic colitis or were unsure of their diagnosis.

While most of the cases received either a letter or phone call with the pathology results, the authors emphasized the importance of considering whether patients with a new diagnosis of microscopic colitis might benefit from a follow-up visit in the gastroenterology clinic for education and treatment. These results highlight how clear communication is needed to address next steps after a diagnosis of the chronic disease.

"We were surprised that certain patients were unaware of their diagnosis and that some of the patients who remained symptomatic were not being treated with prescription medications because we would hope that patients understand their colonoscopy results and receive treatment for any ongoing symptoms," said Redd. "Identifying and addressing gaps in the communication of diagnostic results is an important area for future research."

What is typically experienced with microscopic colitis and other causes of chronic diarrhea are similar symptoms such as watery diarrhea, pain in the abdomen, urgent need to have a bowel movement, fecal incontinence and weight loss. The first-line therapy recommended for microscopic colitis is budesonide. However, findings show 46% of cases received that kind of treatment.

Also, just 26% of diarrhea controls with significant enough symptoms to warrant diagnostic colonoscopy were offered prescription treatment—showing how these patients were likely undertreated. In addition, many cases continued to experience ongoing loose stools, urgency, and fecal incontinence at one year, providing further evidence that patients should be offered follow-up appointments to assess how they are responding to treatment.

The final finding examines the magnitude of symptoms at one year follow-up. In the study, 15% of microscopic colitis cases reported nocturnal stools, 28% abdominal pain, 40% fecal urgency, 32% weight loss, and 21% fecal incontinence. The Microscopic Colitis Disease Activity Index (MCDAI), a tool used to assess disease severity and quality of life, showed significant improvement in microscopic colitis cases compared to controls at a one-year follow-up, only 37% of controls had a an improved MCDAI score.

Based on these results, cases showed improvement in symptoms whether or not they were treated with budesonide. As far as controls, symptomatic follow-up was either similar or more severe than cases.

"Hopefully, these findings will help increase awareness of the importance of communicating diagnostic colonoscopy findings as well as assessing and treating persistent symptoms following an initial diagnostic evaluation," said Redd.

There is substantial symptom overlap between microscopic colitis and other causes of chronic diarrhea, Redd said, so much so that it makes it harder for providers to reliably distinguish the disease from other common conditions, like irritable bowel syndrome. Researchers concluded that colonoscopy should be considered for certain patients with diarrhea who do not respond to initial treatment or who are at higher risk for microscopic colitis.

Furthermore, follow-up appointments, education, and communication can be used to empower patients as far as understanding the implications of a new microscopic colitis diagnosis and how to manage the disease.