A man in his 50s was referred to the hospital with fever, right lower abdominal pain, and bloody diarrhea. Based on computed tomography images and characteristic varioliform erosions observed during the colonoscopic examination, the patient was diagnosed with fulminant amebic colitis. Intravenous metronidazole was administered immediately. After symptom improvement, a second colonoscopic examination revealed inflammation localized to the right hemicolon. A right colectomy was performed on the 75th hospital day, and the patient was discharged without further problems. Prompt antiamebic therapy based on early endoscopic diagnosis was effective in quelling colonic inflammation in a life-threatening case of acute fulminant amebic colitis. Moreover, colonoscopic reexamination was useful in determining the extent of inflammation and minimizing colon resection.

The Japanese guidelines for the treatment of gastric cancer recommend nivolumab as third-line chemotherapy for metastatic gastric cancer. We report a case of gastric cancer exhibiting a durable response after the discontinuation of nivolumab due to the early onset of immune-related adverse event (irAE). A 64-year-old man with advanced HER2-positive gastric cancer and distant lymph node metastasis received nivolumab as fourth-line therapy. After two courses of nivolumab, the lymph nodes showed progression. However, the treatment was discontinued because of interstitial pneumonia as an irAE. Disease regression was sustained for approximately 11 months without the readministration of nivolumab.

A 71-year-old man developed ulcerative colitis (UC) at 48 years of age. As a steroid-dependent case with poor UC control, the patient was treated with azathioprine, which resulted in clinical remission. However, a blood test revealed pancytopenia. Bone marrow examination confirmed the diagnosis of myelodysplastic syndrome (MDS). During the patient's clinical course, multiple round ulcers appeared in the terminal ileum. We suspected concomitant "colitis-like intestinal Behçet's disease" (BD). Treatment with adalimumab resolved the ulcers. To the best of our knowledge, this is a rare case of intestinal BD accompanying UC after MDS.

A 55-year-old man presented with vomiting and upper abdominal pain. Two months later, computed tomography revealed jejunal wall thickening and contrast enhancement. Double-balloon endoscopy revealed severe jejunal stenosis and mucosal prolapse. The patient was diagnosed with stenotic ischemic small bowel inflammation and underwent partial small bowel resection. Clinicians should consider intraperitoneal band formation in the differential diagnosis of patients without a history of abdominal surgery or trauma. Surgical resection should be considered to prevent strangulation ileus.

A 44-year-old man with a history of chronic alcoholic pancreatitis and Crohn's disease presented with abdominal pain. Computed tomography revealed pancreatic calculi in the head of the pancreas and a dilated pancreatic duct. The patient was diagnosed with an acute exacerbation of chronic pancreatitis due to the impact of pancreatic calculi on the main pancreatic duct. During the clinical course, the movement of pancreatic calculi to the major papilla was confirmed, leading to obstructive jaundice. Endoscopic treatment with sphincterotomy of the pancreatic duct was successful. Herein, we report the case of an unusual clinical course involving obstructive jaundice caused by the movement of pancreatic calculi.