An unusual presentation of ischiorectal abscess.

A 49 year old male patient was admitted with a seven day history of fever and incontinence of fluid faeces and painful swelling of the left thigh. He had schizophrenia and had been on stelazine for 10 years. During the present illness he had received treatment for malaria and typhoid. He was referred to Aga Khan University Hospital with a possible diagnosis of femoral vein thrombosis. On examination, he looked toxic, temperature was 104°C, pulse 120/minute, abdomen slighily distended, fluid thrill was present and bowel sounds were normal. The left thigh was warm and its circumference increase compared to the right. All peripheral pulses were palpable. Rectal examination showed an ischio-rectal abscess of horseshoe variety with multiple sinuses discharging pus. Plain films of the abdomen showed some distended loops of small bowel suggesting ileus and the possibility of a soft tissue mass in the left side of the pelvis. The white cell count was 30.2x10 dl, routine hematological and biochemical investigations including random blood sugar were normal. U-scan of the abdomen was unrewarding; doppler studies showed a patent left femoral vein. The patient was examined under anaesthesia and a large ischiorectal abscess was drained. A thorough search was made for an internal opening, which was not found. The organisms cultured from the pus were E. coli and klebsiella. Following this procedure the patient did not improve, continued to be toxic and the white cell count remained elevated. CAT scan of the abdomen and pelvis showed a large abscess cavity starting at the lower pole of the left kidney and extendingdown to the retroperitoneal space lateral and posterior to the psoas muscle then finding its way anterior to the left iiacus muscle. The abscess further tracked down into the anterior thigh till the level of the greater trochanter. Medially it tracked along the left lateral wall of the pelvis and appeared to be continuous with the apex of the ischiorectal fossa. There was large amount of gas in the abscess cavity at various sites. Under CT guidance a size 20 Pr drain was inserted into the abscess cavity, from an extra peritoneal posterior approach, 900cc of pus was drained. With this valuable information a further EUA was performed. The retroperitoneal abscess was drained extraperitoneally and the thigh was drained by means of a separate vertical incision. The ischiorectal cavities were reexplored and communication with retroperitoneal space was confirmed. Thereafter there was remarkable improvement in the patient’s condition. Two further dressings under anaesthesia were required for residual debris. He was discharged after 19 days hospital stay.