Cholangitis after biliary reconstruction is a relatively common complication encountered in hepatobiliary pancreatic surgery. Furthermore, with improved surgical outcomes, there are more opportunities to address cholangitis, which is a late complication. Several reports have been made regarding the risk of developing postoperative cholangitis. Some reports indicate that the risk of cholangitis after biliary reconstruction is affected by benign diseases, an extended operating time, elevated CRP levels, elevated ALP levels, chemotherapy, recurrence, male sex and the presence of postoperative complications [2, 3, 8], while others report that no specific cause can be identified [7, 9]. Regarding the time of onset, postoperative cholangitis has been reported to occur within 2 months to 82 months [7], but most cases occur within 2 years [8, 9]. Regarding the frequency of cholangitis, one report revealed a frequency of more than 10 times, as in the present case, in approximately one-quarter of cases [8]. Although postoperative cholangitis has been reported as described above, there are several issues that need to be addressed. First, the definition and severity of postoperative cholangitis were unclear in cases reported prior to the development of the TG13 guidelines [10]. Because there is now a uniform standard, postoperative cholangitis should be validated based on the definition of the TG18 guidelines in the future [11]. Second, there is a lack of uniformity in terminology as well as in the pathogenesis of the disease. The fact that the same condition has been reported under different names, such as “afferent loop syndrome,” “sump syndrome,” and “postoperative cholangitis,” is also problematic [12, 13]. Since this condition is frequently encountered in the postoperative period, it is desirable to have a unified terminology and definition of the condition in the future. Third, most reported cases of postoperative cholangitis are discussed together with and without stenosis. Although cholangitis can occur in both cases, the pathophysiology and treatment are different, so the discussion should be separate. In clinical practice, it is important to evaluate patients with postoperative cholangitis for the presence of obstruction. The diagnosis is relatively easy in the presence of obstruction, such as anastomotic stenosis or stones in the bile duct. In some cases, stones in the Roux-en-Y intestinal tract have been reported, resulting in cholangitis [14]. Endoscopic, percutaneous, or surgical treatment is indicated for each cause, and symptoms improve when the obstruction is removed. On the other hand, in most cases, cholangitis is diagnosed clinically when fever, abdominal pain, and elevated hepatobiliary enzyme levels are observed without any other apparent cause. Most cases are treated with antimicrobial agents, because the symptoms are mild and not frequently recurrent, so the search for the cause of the disease does not extend to the treatment of the disease in most cases. However, it is also true that there are patients, such as the present patient, in whom symptoms recur frequently and quality of life declines markedly. In a recurring case, such as the present case, it is essential to exclude obstruction and confirm the presence of reflux and stasis by imaging studies to determine a treatment plan. The pathophysiology of postoperative nonobstructive recurrent cholangitis reportedly has two causes [14]: a mechanical effect due to adhesions and flexion of the afferent loop, and a functional effect due to dysmotility of the vagal denervation or proximal disconnection of the afferent loop from the main pacemaker in the duodenum. No mechanical cause was observed in the present case, so we assumed a functional cause. Endoscopy is useful in excluding obstruction, and if stenosis is detected, it is also useful in diagnosing benign or malignant conditions and treating the obstruction at the same time. Percutaneous transhepatic cholangiography, MRCP, and DIC–CT may also be useful in assessing the presence of stenosis. The presence of orally administered gastrografin in the afferent loop or biliary tree is the most standard evaluation of reflux and stagnation. Some reports have reported that scintigrams might also be useful [13]. The above tests should be used to determine the indication for surgery. Some studies have suggested that a longer afferent loop or Roux-en-Y limb is a factor that prevents reflux and stasis in patients with biliary reconstruction [15, 16], but there are also reports that shorter limb lengths are associated with fewer complications, so a certain view has not been reached [17]. In this case, the indication for surgery was also determined after careful consideration, referring to previous cases in which surgery was performed for nonobstructive retrograde cholangitis that developed after biliary reconstruction surgery [4, 5, 18, 19]. The procedure was determined with reference to the Roux-en-Y extension to increase the distance between the route of oral intake and the bile duct jejunal anastomosis, among others [5]. Other reports have described cases in which a valve was created to prevent reflux [4] or the reconstructive configuration was changed to prevent reflux [18, 19], with good results. It is important to consider effective surgical techniques that are appropriate for the cause of the reflux. The indication and timing of surgery for postoperative nonobstructive recurrent cholangitis should take into account the severity of the patient’s condition and the appropriateness of the procedure. Since many cases can be treated conservatively, surgery should be considered for severe symptoms, such as liver abscess, sepsis, or when symptoms are frequent and cause a significant decrease in quality of life, after confirming that reflux is clearly present. It is important to fully consider each case individually. In addition, recent advances in endoscopic treatment have led to reports of the effectiveness of stenting with antireflux valves, which is considered less invasive [20]. This is a promising, minimally invasive treatment for patients who have recurrent postoperative cholangitis but cannot tolerate surgery.