Ultrasound-guided transversus abdominis plane (TAP) block is considered to be one of most prevalent and effective adjuvant analgesic methods for various abdominal surgeries. However, whether TAP blocks can be used alone as an effective anesthetic technique in minor abdominal operations has rarely been reported. Here we presented a 66-year-old male who had sustained right somatic dysfunction and mild brain dysfunction caused by cerebral infarctions and poorly treated hypertension. The patient received a confine operation of transverse colostomy to alleviate an intestinal obstruction caused by rectal cancer. A 22G needle was advanced in the plane under ultrasound guidance until it reached the TAP. A total of 10 mL 0.375% ropivacaine with 5 mg dexamethasone and 10 μg dexmedetomidine was injected into the TAP. The operation went stably and smoothly without any complaints. After the operation, the patient returned to the care of the surgical recovery staff with patient-controlled intravenous analgesia (PCIA) containing 0.7 mg/kg oxycodone and 2.5 μg/kg dexmedetomidine. During the perioperative period, the elderly patient did not experience apparent or unbearable pain. All these evidences indicated the ultrasound-guided subcostal and lateral TAP block was a simple and effective procedure for transverse colostomy in a high-risk elderly patient.