Autophagy refers to the process involving the decomposition of intracellular components via lysosomes. Autophagy plays an important role in maintaining and regulating cell homeostasis by degrading intracellular components and providing degradation products to cells. In vivo, autophagy has been shown to be involved in the starvation response, intracellular quality control, early development, and cell differentiation. Recent studies have revealed that autophagy dysfunction is implicated in neurodegenerative diseases and tumorigenesis. In addition to the discovery of certain disease-causing autophagy-related mutations and elucidation of the pathogenesis of conditions resulting from the abnormal degradation of selective autophagy substrates, the activation of autophagy is essential for prolonging life and suppressing aging. This article provides a comprehensive review of the role of autophagy in health, physiological function, and autophagy-related disease.

Although primarily a respiratory illness, several studies have shown that COVID-19 causes elevation of liver enzymes and various gastrointestinal (GI) symptoms. The aim of this study was to undertake a systematic review and meta-analysis to determine whether the presence of gastrointestinal (GI) symptoms contributed toward COVID-19 severity, and identify the GI symptoms characteristic of severe COVID-19. We conducted a literature search of PubMed from December 1, 2019, to June 30, 2020, and identified all reports with GI symptoms reported. A meta-analysis comparing the severity of COVID-19 with the presence of liver enzyme elevation and GI symptoms was performed using RevMan version 5.4. Pooled data from 15,305 unique reverse transcriptase-polymerase chain reaction positive COVID-19 patients from 44 studies were analyzed. We found that the severe COVID-19 patients significantly had abdominal pain compared to the non-severe COVID-19 patients (OR = 2.70, 95% CI 1.17-6.27, Z = 2.32, p = 0.02, I 2 = 0%) by analyzed 609 patients of 4 studies who reported both abdominal pain and COVID-19 severity. However, there was no significant difference in the incidence of diarrhea, nausea, or vomiting between the two groups. Thus, this systematic review and meta-analysis demonstrated that abdominal pain could be characteristic of severe COVID-19 infections. Compared with other viral infections that primarily infect the respiratory system, patients with COVID-19 have a slightly lower frequency of diarrheal symptoms with abdominal pain. However, to confirm this, further studies with COVID-19 patients across various countries and ethnicities are required.

The relevance of endoscopic monitoring of ulcerative colitis (UC) has been translated into the new concept of “mucosal healing (MH)” as the therapeutic goal to achieve because a large amount of scientific data have revealed the favorable prognostic value of a healed mucosa in determining the clinical outcome of UC. Recent interest in MH has skewed toward not only endoscopic remission but also histological improvement (so called histological MH). However, we should recognize that there have been no prospectively validated endoscopic scoring systems of UC activity in previous clinical trials. Artificial intelligence (AI)‐assisted endoscopy has been developed for gastrointestinal cancer surveillance. Recently, several AI‐assisted endoscopic systems have been developed for assessment of MH in UC. In the future, the development of a new endoscopic scoring system based on AI might standardize the definition of MH. Therefore, “The road to an exact definition of MH in the treatment of UC has begun only now”.

Familial Mediterranean fever (FMF) in gastrointestinal involvement has been considered rare, but resent reports suggest that FMF causes enterocolitis which is similar endoscopic findings to inflammatory bowel disease. The clinical characteristics and endoscopic findings of FMF with enterocolitis remain unclear. Here, we report a case of an FMF patient who had enterocolitis with stricture of the terminal ileum whose endoscopic and clinical features mimicked Crohn’s disease. A 23-year-old man who was diagnosed with FMF 10 years ago presented with abdominal pain and diarrhea. Colonoscopy showed terminal ileitis and aphthous colitis; however, these findings, including the histopathology, did not confirm Crohn’s disease. Therefore, we diagnosed FMF with enterocolitis and administered anti-interleukin-1β monoclonal antibody (canakinumab). The patient’s symptoms improved with treatment, but after 1 year, lower abdominal pain recurred. Colonoscopy revealed a stricture of the terminal ileum. Endoscopic balloon dilation relieved his symptoms. At present, he has been followed up without surgical treatment by endoscopic balloon dilation every 6 month. Clinicians should be aware that FMF accompanied with enterocolitis may resemble Crohn’s disease.