Gastrointestinal Sequelae of COVID-19: Investigating Post-Infection Complications-A Systematic Review

Abstract

Gastrointestinal (GI) complications are significant manifestations of COVID-19 and are increasingly being recognized. These complications range from severe acute pancreatitis to colitis, adding complexity to diagnosis and management. A comprehensive database search was conducted using several databases. Our inclusion criteria encompassed studies reporting severe and long-term GI complications of COVID-19. Digestive disorders were categorized into infections, inflammatory conditions, vascular disorders, structural abnormalities, other diagnoses, and undiagnosed conditions. Of the 73 studies that were selected for full-text review, only 24 met our inclusion criteria. The study highlights a broad range of gastrointestinal complications following COVID-19 infection (excluding liver complications, which are examined separately), including inflammatory conditions, such as ulcerative colitis (UC), acute pancreatitis, and multisystem inflammatory syndrome in children (MIS-C). Other GI complications were reported such as vascular disorders, including diverse thrombotic events and structural abnormalities, which ranged from bowel perforations to adhesions. Additionally, undiagnosed conditions like nausea and abdominal pain were prevalent across different studies involving 561 patients. The findings emphasize the substantial impact of COVID-19 on the GI tract. Ongoing research and monitoring are crucial to understanding the long-term effects and developing effective management strategies for these complications.

Keywords: COVID-19; COVID-19 and gut; COVID-19 complications; SARS-CoV-2; digestive tract gastrointestinal tract; long-COVID; post-COVID sequelae.

Figure 1

Screening and study-selection protocol.

Figure 2

Types of GI tract (except liver) injury/disorders post-COVID-19 infection as reported by 24 studies and their outcomes. The number on each segment shows the number of patients. The inflammatory disorders included 5 patients, of which 1 recovered, 2 did not recover, and the outcome was not reported for the other 2 patients. Disorders with GI infections included 68 patients, of which 1 recovered, 2 did not recover, and the outcome was not reported for 65 patients. Disorders caused by vascular problems included 7 patients, of which 1 recovered, 4 did not recover, and the outcome was not reported for 2 patients. NR: Not reported.

Figure 3

Types of diagnosed GI tract (except liver) injury/disorders post-COVID-19 infection, including inflammatory (a), infections (b), vascular (c), and structural (d). The number in each section shows the number of patients. (a): Inflammatory disorders, as reported by five studies. Numbers for acute hepatitis and acute gastritis were NR. (b): Disorders caused by GI infections as reported by five studies. Numbers for Cryptosporidium spp. and H. pylori infections were NR. (c): GI vascular disorders, as reported by six studies. (d): GI structural disorders, as reported by seven studies. NR: Not reported. UC: Ulcerative colitis; MIS-C: multisystem inflammatory syndrome in children; qPCR: quantitative polymerase chain reaction; SMA: superior mesenteric artery; SMV: superior mesenteric vein; SBO: small bowel obstruction.

Figure 4

Other diagnosed or undiagnosed post-COVID-19 GI disorders. The number in each section shows the number of patients. (a): Dyspepsia, anorexia, and other diagnosed GI disorders reported post-COVID-19 infection, as reported by 13 studies. There are 10 patients in Figure 4a who were diagnosed with GERD, SIBO, gastric ulcers, duodenal ulcers, hematochezia, erosions and luminal bleeding of colon, ascites, extensive pneumatosis in gastric intestinalis, hemorrhagic necrosis in gastric and extensive small bowel mucosa, and esophageal dysphagia. Also, the number of patients who developed IBS post-COVID-19 was reported as 25%, and the number of patients who developed PUD was NR. (b): Reported symptoms/undiagnosed GI disorders post-COVID-19 infection. NR: Not reported; GERD: gastroesophageal reflux disease; SIBO: small intestinal bacterial overgrowth; PUD: peptic ulcer disease.