Globally, only 1%–3% of documented COVID-19 cases occur in children. Nevertheless, children exhibit a higher propensity for gastrointestinal (GI) symptoms, with approximately 25% displaying at least one GI symptom. In some instances, GI symptoms may be the sole presenting symptoms of COVID-19 in children. The most reported GI symptoms are abdominal pain, diarrhea, and nausea/vomiting (1, 2).

A significant dilemma exists concerning the etiology of acute abdominal pain in children and the complications associated with multisystemic inflammatory syndrome in children (MIS-C). A diverse range of potential causes includes mesenteric adenitis, appendicitis, abdominal fluid collection, pancreatitis, terminal ileitis, cholecystitis, and intussusception (3–5).

Extensive research has been conducted on the gastrointestinal manifestations of COVID-19 in pediatric cases, including acute abdominal pain. However, currently, no study provides a quantitative analysis of abdominal pain cases from a surgical standpoint (4, 6, 7).

COVID-19 can induce abdominal pain resembling that in abdominal emergencies, particularly in MIS-C cases. These patients may exhibit symptoms akin to acute enteritis or an acute abdomen requiring surgery, posing a risk of misdiagnosis (8). According to AL Vecchio et al. (4), only 60% of children with COVID-19 who underwent surgery for acute appendicitis received a histologically confirmed diagnosis of acute appendicitis. Additionally, certain studies have indicated instances where children underwent emergency abdominal surgery for acute conditions only to have negative intraoperative diagnoses (9–12).

This study explored how the COVID-19 pandemic has affected pediatric patients’ presentation, assessment, and surgical management of acute abdominal pain.

The coronavirus pandemic represents a medical paradigm shift, influencing our comprehension and treatment strategies for various illnesses. The decision to undergo surgical treatment can be problematic for children with COVID-19 due to the increased risk of postoperative complications. Therefore, it is generally advisable to avoid surgery unless deemed necessary (16, 17).

The current investigation identified 31 patients with appendicitis. The first case revealed intraoperative findings of a congested appendix with mesenteric adenitis and ileitis accompanied by peritoneal fluid. Unfortunately, this case experienced a challenging postoperative period, which caused the development of MIS-C. In the second case, diagnostic laparoscopy exhibited findings similar to the first but was managed conservatively. Subsequently, four complicated cases underwent appendectomy initially, while the remaining 25 cases received conservative treatment, with only three requiring subsequent surgery.

Overall, surgery was conducted in 29% of cases presenting with appendicitis. COVID-19 can lead to acute abdomen that mimics appendicitis, as supported by existing literature indicating cases where appendectomy was performed with histologically proven negative results (4, 6, 16). Conversely, during COVID-19, severe gastrointestinal involvement, including ileitis and mesenteric adenitis, can occasionally mimic appendicitis (3, 18, 19). Similar to our findings, there is a noticeable shift toward conservative treatment of appendicitis during the COVID-19 pandemic (20–24).

Another significant finding involves 17 cases presenting with generalized abdominal pain. The initial laparotomy in the first case revealed peritoneal fluid in the pelvis, right and left iliac fossa, hepatorenal pouch, mesenteric adenitis, and edematous intestine, necessitating drainage. The second case underwent laparoscopy, displaying diffuse edematous terminal ileum and colon with intra-abdominal fluid and mesenteric adenitis. Subsequently, two cases received drainage in the right iliac fossa, while the remaining 14 cases were treated conservatively with spontaneous resolution, except in one case where laparotomy revealed sigmoid colon perforation. In four cases, conservative treatment was employed, and anticoagulant therapy was administered due to suspicion of mesenteric thrombosis based on duplex study findings of mesenteric vessels.

One case showed multiple perforations in the rectosigmoid region and descending colon. The involvement of the sigmoid colon may be attributed to evidence suggesting that the vascular effects of COVID-19, such as ischemic colitis, tend to impact the left colonic flexure and sigmoid colon more than the distal rectum, concerning their dual blood supply (25, 26).

Conservative methods proved effective in treating diffuse abdominal pain. This aligns with other studies recommending conservative treatment with regular reassessment, as most cases naturally resolve without intervention. Moreover, multiple lines of evidence indicate that intraperitoneal fluid results from increased intestinal permeability, and bacteriological examinations yield negative results (4, 5, 27).

Among patients in our study, 14 cases presented with symptoms resembling acute cholecystitis, particularly abdominal pain in the right hypochondrium. Ultrasound examinations revealed mild hepatomegaly with gallbladder wall thickening and mesenteric adenitis in three cases, mild hepatomegaly with a small amount of free fluid in six cases, and gallbladder wall thickening and edema with mesenteric adenitis in five cases. All these cases responded to conservative treatment.

The pathogenesis of hepatobiliary involvement is attributed to mild sinusoidal lymphocytic infiltration and sinusoidal dilatation. These factors result in mild pain and manifest on ultrasound as mild hepatomegaly with various gall bladder-related changes (28, 29).

Previous literature has documented intussusception as a cause of abdominal pain during COVID-19. However, no documented evidence of transient intussusception associated with COVID-19 exists in the literature (4). Transient intussusception is a distinct phenomenon that may impact children (30–32). The pathogenesis of transient intussusception associated with COVID-19 is not clearly defined, but it may be attributed to pathological features such as mesenteric adenitis, bowel wall thickness, and edema associated with COVID-19. This pathogenic mechanism could contribute to the occurrence of intussusception, as observed in cases involving other intestinal viruses (4, 33).

MIS-C is a systemic hyperinflammatory syndrome secondary to COVID-19 infection; its diagnostic criteria include abdominal pain, diarrhea, vomiting, colitis, ileitis, abnormal liver function tests, and ascites (14, 15, 34). It impacts multiple organs and can lead to shock with heart dysfunction, with predominant involvement of the gastrointestinal tract observed in 70%–90% of cases. The gastrointestinal symptoms associated with MIS-C may mimic those of an acute abdomen (33, 35). In this study, 9 cases with MIS-C presented with diffuse abdominal pain and ultrasound findings of mesenteric adenitis and ileitis with fluid collection. Drainage was performed in 2 cases, while the remaining 7 cases responded well to conservative treatment. Similarly, Lo Vecchio et al. performed drainage in 5 out of 21 children (23.8%), with most fluid collections resolving over time and the fluid being bacteriologically sterile (4).

Abdominal pain in MIS-C can manifest in different presentations, such as pseudo-appendicitis pain and diffuse abdominal pain. The associated pathological changes in the abdomen are diverse and may include mesenteric adenitis, ileitis, and thickening of the bowel loop, with a predominant presence of fluid collection (36, 37). Appendicitis in MIS-C is typically associated with a patent lumen, serositis, and perivasculitis. Conservative treatment approaches are recommended for these cases (4, 38).

Acute abdominal pain in children has traditionally been evaluated surgically to exclude common causes such as appendicitis or perforated intestine. However, the COVID-19 pandemic has necessitated a shift in approach due to similarities between COVID-19 and other coronaviruses affecting gastrointestinal enterocytes and causing abdominal pain (39). The primary challenge now is distinguishing between surgical causes of acute abdominal pain and those related to COVID-19, emphasizing the need for precise diagnostic methods to prevent medical errors and unnecessary surgeries.

While laparoscopic surgery is considered the gold standard for appropriate cases of acute abdominal pain, our study utilized laparoscopy in only 2 cases (11.1%) out of 18 patients. Initially, there was concern about the safety of laparoscopy during the pandemic, with some studies suggesting an increased risk of virus particle aerosolization during CO₂ insufflation (40, 41).

Despite the WHO declaring on May 5, 2023, that COVID-19 is no longer an international public health emergency, the disease remains prevalent. Therefore, it is essential to consider COVID-19 as a potential cause of abdominal pain in all cases.

Our study's relatively small number of cases can be attributed to several factors. COVID-19 presentation in pediatric patients is less common than in adults, and respiratory symptoms are more prevalent than abdominal ones. Additionally, some cases were transferred to other centers following local protocols. Despite these limitations, our retrospective study provides valuable data on a globally significant disease. It captures a diverse range of presentations of acute abdomen in pediatrics, highlighting the need for further research to enhance our understanding of this complex issue.

Acute abdominal pain in children during COVID-19 is a common occurrence, often resolving without surgical intervention due to the self-limiting nature of most gastrointestinal manifestations. It is crucial to consider COVID-19 as a differential diagnosis in patients presenting with acute abdominal pain, particularly in cases of atypical appendicitis and intussusception. Meticulous evaluation and accurate diagnosis are essential to avoid unnecessary surgical interventions in children with persistent abdominal pain.