A vaginally delivered, full-term 9-month-old girl with a complaint by her mother of fecal soiling from her vagina since birth; constipation of 2 months duration with pain on defecation, no fever nor vomiting. The examination result was that the abdomen was slightly rigid with no palpable masses; the native anus was within the normal anatomical position, shape, and size. The interrelated perineal examination displayed normal external genitalia with fecal soiling (Fig. 1). Rectovaginal fistula was suspected. Therefore, she underwent EUA to confirm a diagnosis and possible surgical excision of the fistula with the repair of the area. Upon inserting a tube inside the fistulous opening, it did not come out through the anus as expected.

Perineal examination displayed a native anus that is within the normal anatomical position, shape, and size, with normal external genitalia and fecal soilings

A fistulogram was performed using gastrografin contrast, which showed narrowed segment at the beginning with a nearly normal colon; based on this, the radiologist suggested an initial diagnosis of a high perianal fistula with an internal opening at the sigmoid colon (Fig. 2).

A fistulogram showing narrowed segment distally with a nearly normal colon proximally

Not convinced with the radiology opinion, we decided to do another trial under GA with methylene blue dye injected through a tube inserted inside the fistula and gauze inserted inside the anus. The dye passed through the colon without any passage of methylene blue through the anus as evidenced by a clean gauze, suggesting two separate systems with the absence of communication at that level and a wrong initial diagnosis. A new diagnosis of colonic duplication was discussed.

A double contrast study by barium enema and fistulogram at the same time was performed (Figs. 3 and 4).

Plain abdominal X-ray before a double contrast study

Simultaneous contrast enema and fistulogram study

Radiologists abstain from giving us a report about the findings of the study may be due to a lack of experience in such rare cases. From our experience with similar cases after studying the films, the diagnosis of colonic duplication was more likely.

To be sure of the diagnosis, a diagnostic confirmatory laparoscopy was performed. Laparoscopic exploration of the colon confirmed the diagnosis of colonic duplication. It revealed tubular T-shaped colonic duplication with separate lumens from the mid-transverse colon downwards; both colons were found entirely attached at the mesenteric side sharing both vascularity and wall (Fig. 5). The duplicated colonic segment towards the mesenteric side terminated downward at the vestibule.

Laparoscopic exploration of the colon confirming the diagnosis of colonic duplication, from the mid-transverse colon terminating downward at the vestibule

Laparotomy was then done using a lazy transverse incision in the lower abdomen. The duplicated colon was fused to the native colon in a double-barrel fashion (Fig. 6).

Laparotomic exploration showing the duplication at the sigmoid area (on the left) and at the mid-transverse colon (on the right)

A side-to-side (window) anastomosis between the native colon and the duplicated colon was performed using a GIA stapler at the descending segment, converting 6 cm into a single-wide lumen (Fig. 7).

A side-to-side (window) anastomosis between the native colon and the duplicated colon was performed using a GIA stapler

Duplicated colon was cut at the sigmoid level; the proximal end was used to create an end-to-side anastomosis with a normal colon—these two minimally invasive procedures ensure complete drainage of the content of duplicated colon into the normal colon (Fig. 8).

Duplicated colon was cut at the sigmoid level; the proximal end was used to create an end-to-side anastomosis with the normal colon

The distal segment of the duplicated colon was opened down to peritoneal reflection; stripping of the mucosa of the distal duplicated colon down to the fistula opening was done (Fig. 9).

The distal segment of the duplicated colon was opened down to peritoneal reflection (on the left); stripping of the mucosa of the distal duplicated colon down to the fistula opening (on the right)

The stripped mucosa was transfixed to the feeding tube inserted through the fistula and inverted totally out of the fistula opening; it was cut, and the area was repaired to close the site of the fistula (Fig. 10).

The stripped mucosa was transfixed to the feeding tube inserted through the fistula and inverted totally out of the fistula opening; then, it was cut and closed

The biopsy pathology report revealed unremarkable colorectal mucosa and submucosa with mild chronic inflammation, with no evidence of malignancy.

The patient was discharged on day 10 in good general condition after an uneventful postoperative clinical course. She was passing stool normally through the anal opening. At follow-up evaluation, the patient was doing well without pain or constipation.