On 1 November 2020, a 50-year-old Han woman presented with a 6-month history of recurrent distending pain in the right upper abdomen and was admitted to the Department of Gastrointestinal Surgery at The First Affiliated Hospital of Wannan Medical College. The abdominal pain was paroxysmal and accompanied by nausea and vomiting. She had no diarrhea, no black or bloody stools, and no fever or chills. Physical examination revealed tenderness and rebound pain in the middle and upper abdomen, no muscle tension, no palpable abdominal mass, no signs of oral or vulvar ulcers, no perianal fistula, and no joint rash. Laboratory investigations revealed normocytic anemia (hemoglobin, 97 g/L), hypoproteinemia (albumin, 29.6 g/L), and elevated inflammatory marker levels [C-reactive protein (CRP), 10.47 mg/L; erythrocyte sedimentation rate (ESR), 28 mm/h]. The platelet count was 305 × 109/L, exceeding the upper limit of normal. Positive results were obtained for fecal occult blood, tuberculosis antibody, tuberculosis infection based on the number of spot-forming T cells (T-SPOT.TB test), and tuberculin purified protein derivative. No obvious abnormality was observed in the white cell count, blood coagulation, routine laboratory evaluation before blood transfusion, tumor markers, and an acid-fast bacillus sputum smear. Because of the patient’s normocytic anemia and right upper abdominal pain, enhanced computed tomography (CT) of the whole abdomen was carried out first. The results indicated obvious thickening and strengthening of the cecum and ascending colon with multiple enlarged lymph nodes, raising the possibility of cancer. Colonoscopy subsequently showed a large circumferential ulcer infiltrating the bowel from the proximal ascending colon to the ileocecal region, and the intestinal cavity was too narrow for passage of the endoscope. Pathologic examination showed acute and chronic inflammation of the mucosa with crypt abscesses, inflammatory exudation, necrosis, and granulation tissue, but no granulomatous inflammation. Because of the mechanical obstruction secondary to the stricture from the ileocecal ulcer, part of the intestine in the right abdomen was dilated with gas and fluid accumulation. After failure of conservative treatment (fasting, gastrointestinal decompression, and anti-infection agents), the patient finally underwent radical right colon resection on 4 November 2020. Postoperative pathologic examination revealed a 7.0- × 4.0-cm ileocecal ulcer. The peri-intestinal wall tissue was infiltrated by numerous acute and chronic inflammatory cells and contained lymphatic follicles. Both the peri-ileal and pericolic lymph nodes showed reactive hyperplasia. On 10 December 2020 (1 month after the operation), the patient was readmitted to the hospital because of abdominal pain. Abdominal CT revealed intestinal obstruction and pelvic effusion. After symptomatic treatment consisting of fasting, fluid rehydration, and anti-infection treatment, the patient was discharged with improved symptoms. Six months later, the patient presented to the Department of Gastroenterology because of a 5-day history of distending pain in the right upper abdomen. Physical examination showed no abdominal tenderness or rebound pain, no palpable abdominal mass, no bulbar conjunctival congestion, no oral or vulvar ulcers, no perianal fistula, and no joint rash or other abnormalities. A plain CT scan indicated irregular thickening of the intestinal wall in the operative area, which seemed to be locally connected to the descending part of the duodenum. Laboratory investigations revealed normocytic anemia (hemoglobin, 100 g/L), hypoproteinemia (albumin, 33.7 g/L), elevated inflammatory marker levels (CRP, 13.77 mg/L; ESR, 50 mm/h), and a high platelet count of 320 × 109/L. Tuberculosis antibody, the T-SPOT.TB test, and tuberculin purified protein derivative were positive. However, negative results were obtained on an acid-fast bacillus sputum smear, fecal occult blood test, blood coagulation profile, tumor marker measurement, autoantibody measurement, and antineutrophil cytoplasmic antibody measurement. Abdominal enhanced CT showed a small amount of exudation in the fatty space around the anastomosis and multiple lymph nodes as well as uneven thickening and edema of the wall of the gastric pylorus. Colonoscopy showed obvious narrowing of the anastomosis with a huge deep ulcer that could not be passed by the endoscope; no abnormalities were found in the remaining intestinal tract. Pathologic examination showed acute and chronic inflammation of the anastomotic mucosa, inflammatory exudation, necrosis, and granulation tissue. In addition, gastroscopy showed a 3.0- × 4.0-cm giant ulcer at the junction of the descending bulb. The ulcer was covered with yellow slough, and a sinus tract had formed. Moreover, total gastrointestinal CT angiography showed significant thickening of the intestinal wall near the transverse colon, forming a sinus tract at the junction of the antrum and duodenum with a length of about 1.3 cm and width of about 0.2 cm. Further inquiry regarding the patient’s medical history indicated that she had experienced repeated oral ulcers 3 years previously and repeated eye inflammation 5 years previously, neither of which had recurred since then. Based on the above results, specimens of the right half of the colon removed 6 months previously were sent to Run Run Shaw Hospital Affiliated to Zhejiang University for consultation. The pathologic examination revealed vasculitis in the submucosa and subserosa, and the patient was diagnosed with BD. Thus, we ultimately diagnosed BD according to the International Criteria for Behçet’s Disease (ICBD) []. The patient was treated with methylprednisolone (40 mg) and isoniazid (0.4 g) four times daily for 3 weeks, followed by a tapering of prednisone and adalimumab 2 weeks once for 6 months. This resulted in resolution of the patient’s abdominal distension as well as weight gain. Repeat gastroenteroscopy revealed that the intestinal ulcer had significantly improved (Fg. G–I). Repeat laboratory investigations after 6 months of treatment showed the following: hemoglobin, 132 g/L; platelet count, 253 × 109/L; albumin, 44.3 g/L; CRP, 0.88 mg/L; and ESR, 4.7 mm/h.