RESUMO
A 31-year-old man was admitted to our hospital because of upper abdominal pain. He had been diagnosed with ulcerative colitis (UC) at age 28, but the disease has been in remission since then. On admission, he had slight fever, abdominal pain, and bloody stools six times a day, and the serum levels of pancreatic enzyme and IgG4 were elevated. Diffuse enlargement of the pancreas was detected by abdominal computed tomography; furthermore, narrowing of the main pancreatic duct was revealed using endoscopic retrograde cholangiopancreatography. Based on these findings, he was given a diagnosis of autoimmune pancreatitis (AIP) associated with UC. Both diseases improved without using steroids. After discharge, he has not had any recurrence of AIP or UC despite not being on steroid treatment, although the serum IgG4 level has shown a slight tendency to elevate.