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Gastrointestinal symptoms and chronic fatigue may persist months after the COVID-19 virus infection resolves, results of a recent cohort-controlled study suggest.

About 5 months after SARS-CoV-2 infection, relative risks of loose stools, somatization, and chronic fatigue were increased by approximately two- to three fold, compared to individuals who had not been infected, according to study results presented at the annual Digestive Disease Week® (DDW).

These longer-term consequences of SARS-CoV-2 appeared to be more severe in patients who had experienced diarrhea during the acute infection, according to investigator Daniele Noviello, MD, a second-year resident in gastroenterology and hepatology at the University of Milan.

This is the first cohort-controlled study that specifically investigates gastrointestinal symptoms and somatoform disorders, Noviello said in a virtual presentation of the results.

“Based on our data, chronic fatigue, gastrointestinal, and somatoform symptoms may have a common postinfectious origin, and they should be investigated in the follow-up of SARS-CoV-2 patients,” he said.

Links Between SARS-CoV-2 and Gastrointestinal Symptoms

Gastrointestinal symptoms are known to be relatively common during acute infection. According to Noviello, the most frequent gastrointestinal symptom associated with SARS-CoV-2 is diarrhea, occurring in 4% to nearly 40% of patients in case series to date.

However, data on the longer-term gastrointestinal impacts of SARS-CoV-2 remain scarce.

In one noncontrolled cohort study in China, loss of appetite, nausea, acid reflux, and diarrhea were seen in 15%-24% of patients 3 months after the infection, Noviello said. In another cohort study in China, diarrhea and vomiting were reported in 5% of patients 6 months after infection.

In any case, it is known that viral, bacterial, and protozoal infections of the gastrointestinal tract are a risk factor for development of functional disorders including irritable bowel syndrome (IBS), functional dyspepsia, and chronic fatigue, according to Noviello.

Accordingly, the results of the present study suggest that SARS-CoV-2 also “may affect the brain-gut axis in the long term,” Noviello and coauthors wrote in an abstract of the study.

It is plausible that SARS-CoV-2 infection could be a trigger for longer-term gastrointestinal symptoms, especially given the previous evidence linking infections and IBS symptoms, or postinfectious IBS, said Juan Pablo Stefanolo, MD, a physician with the neurogastroenterology and motility section, Hospital de Clínicas José de San Martín, Buenos Aires University.

“If it is demonstrated [that SARS-CoV-2 infection is a trigger], the microbiota-gut-brain axis concept in IBS pathophysiology is reinforced,” Stefanolo said in an interview.

In the meantime, practitioners may want to take into account COVID-19 infection history in the evaluation of a patient with IBS-like symptoms and, in case of a known positive COVID-19 result in an IBS patient, be aware of the possibility of symptom exacerbation, Stefanolo said.

Pandemic in Italy: Unique Study Opportunity

The severe outbreak in the Milan region early in the COVID-19 pandemic provided a “unique opportunity” to assess the long-term impact of infection on gastrointestinal and extraintestinal somatoform symptoms, said Noviello.

The investigators sent an online questionnaire to patients who had a molecular diagnosis of SARS-CoV-2 infection by nasal swab between February and April of 2020. To form a control group, they also sent questionnaires to hospital employees and health care providers who had tested negative over that same time period.

In all, 378 questionnaires were completed by 177 SARS-CoV-2–positive individuals and 201 controls. The SARS-CoV-2–positive patients were somewhat older (about 44 years vs. 40 years for controls), were less often female (40% vs. 61%), had a lower education level, and smoked less than did controls, according to the investigators.

A mean of 4.8 months had elapsed between the time of SARS-CoV-2 infection and when the questionnaires were compiled, said Noviello.

In the acute phase, diarrhea was the most common gastrointestinal symptom among virus-positive individuals, occurring in about 50% compared to 20% of controls (P < .001), data show. Other symptoms reported by 40% of SARS-CoV-2–infected individuals included fever, dyspnea, loss of smell or taste, weight loss, myalgia, arthralgia, and asthenia in the acute phase controls in the acute phase, Noviello said.

Persistent Gastrointestinal Symptoms After SARS-CoV-2

Persistent symptoms included loose stools, as measured by the Bristol Stool scale, occurring in 17.8% of SARS-CoV-2–positive individuals, but only 9.3% of the SARS-CoV-2–negative controls, according to Noviello, with an adjusted risk ratio of 1.88 (95% confidence interval, 0.99-3.54).

Chronic fatigue symptoms, as measured by the Structured Assessment of Gastrointestinal Symptoms questionnaire, were reported by about 30% of SARS-CoV-2–positive patients and about 15% of controls, for an adjusted risk ratio of 2.24 (95% CI, 1.48-3.37), according to Noviello’s presentation.

The mean t-score on the Symptom Checklist–12 for somatoform disorders was higher for the virus-positive patients compared to controls, according to Noviello. The scores were 54.6 and 50.5, respectively, with an adjusted score difference of 3.6 (95% CI, 1.0-6.2).

The longer-term sequelae of SARS-CoV-2 infection might be more severe in individuals who experienced diarrhea during acute infection, according to Noviello. In a post hoc analysis, reports of irritable bowel syndrome and loose stools were significantly higher in SARS-CoV-2–infected individuals who had diarrhea in the acute phase compared to those who did not experience diarrhea, he said.

Somatoform disorder scores were significantly higher, and reports of headache, back pain, and chronic fatigue were significantly more common, in individuals who had diarrhea at the time of SARS-CoV-2 infection, he added.

Noviello and coauthors reported no competing interests related to the study. Stefanolo had no disclosures to report.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.