INTRODUCTION: The prevalence and shedding of fecal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA indicate coronavirus disease 2019 (COVID-19) infection in the gastrointestinal (GI) tract and likely infectivity. We performed a systemic review and meta-analysis to evaluate the prevalence and the duration of shedding of fecal RNA in patients with COVID-19 infection. METHODS: PubMed, Embase, Web of Science, and Chinese databases Chinese National Knowledge Infrastructure and Wanfang Data up to June 2020 were searched for studies evaluating fecal SARS-CoV-2 RNA, including anal and rectal samples, in patients with confirmed COVID-19 infection. The pooled prevalence of fecal RNA in patients with detectable respiratory RNA was estimated. The days of shedding and days to loss of fecal and respiratory RNA from presentation were compared. RESULTS: Thirty-five studies (N = 1,636) met criteria. The pooled prevalence of fecal RNA in COVID-19 patients was 43% (95% confidence interval [CI] 34%–52%). Higher proportion of patients with GI symptoms (52.4% vs 25.9%, odds ratio = 2.4, 95% CI 1.2–4.7) compared with no GI symptoms, specifically diarrhea (51.6% vs 24.0%, odds ratio = 3.0, 95% CI 1.9–4.8), had detectable fecal RNA. After loss of respiratory RNA, 27% (95% CI 15%–44%) of the patients had persistent shedding of fecal RNA. Days of RNA shedding in the feces were longer than respiratory samples (21.8 vs 14.7 days, mean difference = 7.1 days, 95% CI 1.2–13.0). Furthermore, days to loss of fecal RNA lagged respiratory RNA by a mean of 4.8 days (95% CI 2.2–7.5). DISCUSSION: Fecal SARS-CoV-2 RNA is commonly detected in COVID-19 patients with a 3-fold increased risk with diarrhea. Shedding of fecal RNA lasted more than 3 weeks after presentation and a week after last detectable respiratory RNA.

The efficacy and factors associated with patient outcomes for a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (LFD) compared with traditional dietary advice (TDA) based on modified National Institute for Clinical Excellence guidelines for irritable bowel syndrome with diarrhea (IBS-D) in regions consuming a non-Western diet are unclear. We aimed to determine the efficacy of an LFD compared with TDA for the treatment of IBS-D in Chinese patients and to investigate the factors associated with favorable outcomes. One hundred and eight Chinese IBS-D patients (Rome III criteria) were randomly assigned to an LFD or TDA. The primary endpoint was a ≥50-point reduction in the IBS Severity Scoring System at 3 wk. Fecal samples collected before and after the dietary intervention were assessed for changes in SCFAs and microbiota profiles. A logistic regression model was used to identify predictors of outcomes. Among the 100 patients who completed the study, the primary endpoint was met in a similar number of LFD (30 of 51, 59%) and TDA (26 of 49, 53%) patients (∆6%; 95% CI: −13%, 24%). Patients in the LFD group achieved earlier symptomatic improvement in stool frequency and excessive wind than those following TDA. LFD reduced carbohydrate-fermenting bacteria such as Bifidobacterium and Bacteroides, and decreased saccharolytic fermentation activity. This was associated with symptomatic improvement in the responders. High saccharolytic fermentation activity at baseline was associated with a higher symptom burden (P = 0.01) and a favorable therapeutic response to the LFD (log OR: 4.9; 95% CI: −0.1, 9.9; P = 0.05). An LFD and TDA each reduced symptoms in Chinese IBS-D patients; however, the LFD achieved earlier symptomatic improvements in stool frequency and excessive wind. The therapeutic effect of the LFD was associated with changes in the fecal microbiota and the fecal fermentation index. At baseline, the presence of severe symptoms and microbial metabolic dysbiosis characterized by high saccharolytic capability predicted favorable outcomes to LFD intervention. This trial was registered at clinicaltrials.gov as NCT03304041.

INTRODUCTION: Slow colon transit and visceral hypersensitivity are recognized as major pathophysiological mechanisms in irritable bowel syndrome with constipation (IBS-C). However, there is a lack of therapies targeting both abdominal pain and colonic motility. This study was designed to investigate the long-term effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) in patients with IBS-C. METHODS: Fifty-two patients with IBS-C were randomized into 2 groups: daily TEA for 4 weeks (n = 26) and daily sham-TEA for 4 weeks (n = 26). The number of complete spontaneous bowel movements per week (CSBMs/week, primary outcome), Irritable Bowel Syndrome Severity Scoring System, Patient Assessment of Constipation Quality of Life, visual analog scale (VAS) pain score, colonic transit time, and anorectal physiology were evaluated before treatment and at the end of the treatment. Colonic transit was assessed with radiopaque markers. Electrocardiograms were recorded for assessing autonomic functions. RESULTS: (i) TEA improved constipation and abdominal pain. After the treatment, the number of CSBMs/week during the last week in the TEA group was higher than that in the sham-TEA group (3.5 ± 1.6 vs 2.3 ± 0.6, P = 0.002). Similar effects were also noted in the visual analog scale pain score (P = 0.002) and Irritable Bowel Syndrome Severity Scoring System score (P = 0.025). In addition, there was a significant improvement in the quality of life of patients with constipation. The Patient Assessment of Constipation Quality of Life total score was significantly decreased in the TEA group (P = 0.004). (ii) Compared with sham-TEA, TEA improved colon transit (P = 0.002) and increased the threshold of rectal sensation (desire to defecate, P = 0.004; maximum tolerability, P < 0.001). (iii) TEA increased vagal activity, compared with sham-TEA (P < 0.05); at the end of the treatment, the vagal activity was significantly correlated with colon transit and the CSBMs/week. DISCUSSION: TEA improves constipation and symptoms of IBS by accelerating colon transit and reducing rectal sensation, possibly mediated by using the autonomic mechanisms.