Trans-Rectal Drainage of Pelvic Abscess 
Richard Davis 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
Introduction:  
 
Trans-rectal drainage of an abscess in the 
pelvis, performed by a surgeon in the operating room, 
was once a very common technique for dealing with 
pelvic abscesses. In resource-rich settings, this 
technique has been largely replaced by image-guided 
pelvic 
abscess 
drainage 
performed 
by 
an 
interventional radiologist. It remains important in 
settings like ours, however: it can help you avoid a 
laparotomy and its attendant risks. It is especially 
useful in a patient who develops a pelvic abscess 
after a laparotomy for peritoneal sepsis, a not 
uncommon event. The procedure can also easily be 
adapted to a trans-vaginal approach if the abscess can 
be more easily reached in this manner.  
As mentioned above, a common indication is 
development of a pelvic abscess after laparotomy for 
abdominal sepsis. Other indications include pelvic 
inflammatory disease with abscess that has not 
responded to antibiotics, or conditions such as 
perforated appendicitis that lead to an abscess in the 
pelvis. On rare occasions, a perianal abscess will 
drain “upwards” and create an abscess in the pelvis, 
in the supralevator space. Usually such an abscess 
will also have a perianal component that you can feel 
when palpating the perineum. If not, this diagnosis 
can be extremely difficult to make without a CT scan.  
When trans-rectal drainage of an abscess is 
performed in resource-rich settings, the technique is 
as follows: a needle is inserted into the abscess, 
followed by passage of a guidewire, dilation of the 
tract, and placement of a catheter in the abscess. If 
you have access to a guidewire and a small pigtail 
catheter, you can adapt the techniques described in 
this chapter to drain the abscess using these items.  
There are three big limitations to this 
technique.  
• You must be certain of the abscess’s location. 
Often, but not always, this requires a CT scan, 
especially for the inexperienced clinician. 
However, if the clinical scenario, physical 
examination and pelvic ultrasound all fit, a CT is 
not necessary. All of these are described further 
below.  
• The abscess must be mature. That is, it must be 
walled 
off 
and 
contained, 
not 
freely 
communicating with the peritoneum. If it is not 
contained, making a hole in the rectum that 
communicates with the peritoneal cavity will not 
make the patient better, it will make them much 
worse. Usually it takes 4-5 days for an abscess in 
the abdomen to be walled off. On CT scan, the 
finding of “rim enhancement,” the uptake of IV 
contrast by the inflammatory wall of the abscess, 
confirms this fact. 
 
Axial CT scan of the pelvis in a patient who underwent 
laparotomy for perforated duodenal ulcer one week prior. The 
abscess cavity (Red dot) is clearly seen anterior to the rectum 
(Green dot) and posterior to the uterus (Blue dot). The bladder 
is anterior to the uterus, containing the balloon of a urinary 
catheter (Yellow dot). Note also that the rim of the abscess 
(Black arrow) enhances with contrast, confirming that this is 
an abscess and not a pelvic fluid collection. This abscess was 
successfully drained by a trans-vaginal approach.  
 
• If you cannot feel the abscess on digital rectal 
examination, you are not likely to be able to reach 
it through the anus. Your options are image-
guided drainage, if this is available to you, or 
laparotomy.  
 
The patient with a pelvic abscess will have a 
history that explains the presence of the abscess. 
Sometimes, as with perforated pelvic appendicitis, 
this history is difficult to distinguish and may be 
apparent only in hindsight. Other times, as after 
laparotomy for perforated viscus, you may know that 
the patient is not doing well and be searching for a 
source of infection. See Recognizing Postoperative 
Intra-Abdominal Sepsis. The patient may have 
obstipation or diarrhea due to irritation of the 
Trans-Rectal Drainage of Pelvic Abscess 
Richard Davis 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
intestines by the adjacent abscess. They may 
complain of low back pain or pain on walking.  
On physical examination, the patient appears 
ill, usually septic with tachycardia and an elevated 
white blood cell count. Urinalysis may show 
leukocytes or blood. Usually the abdomen is soft and 
non-tender, except possibly to deep palpation behind 
the pubic symphysis. With a fitting clinical history, a 
tender mass on digital rectal examination that is 
palpable outside the rectum secures the diagnosis.  
In all patients, examine the perineum very 
carefully to rule out a perianal abscess that 
communicates with a pelvic abscess. In this case, you 
will drain the external portion of the abscess and 
probe the inside of the cavity aggressively, following 
it to its deeper component and breaking up any 
loculations, rather than performing the operation 
described here.  
Always do a rectal examination in all patients 
and a pelvic examination in a woman. If a woman 
has a pelvic abscess due to inflammatory disease, she 
will have cervical motion tenderness. This condition 
is usually treated first with antibiotics; drainage of 
the abscess is reserved for patients who fail this 
treatment.  
If you do not have a CT scan, you may still 
do this procedure on a patient whose clinical history 
and exam are consistent with pelvic abscess. You 
must not attempt this procedure if you cannot feel the 
mass on rectal exam. It is possible that your 
examination will be limited by patient pain or anxiety; 
in this case, consent them for this procedure as well 
as laparotomy if it fails, then perform a thorough 
rectal examination with the patient in lithotomy 
position (up in stirrups) after they are under 
anesthesia.  
Trans-rectal drainage of pelvic abscess 
proceeds in the following steps 
• Be certain of the diagnosis, as described above 
• Position the patient in lithotomy position after 
induction of anesthesia 
• Aspirate the abscess with a needle to confirm its 
position 
• Make a cruciate incision at the same location 
• Irrigate the cavity thoroughly 
• Place a drain and secure it to the cut edge of the 
abscess 
 
Steps: 
1. Either general or spinal anesthesia is acceptable 
for this operation. The patient must be fully 
relaxed from the waist down, so “saddle block” 
is generally not sufficient except in a very 
compliant patient. 
2. If you have an ultrasound machine, visualize the 
abscess cavity adjacent to the bladder.  
 
Axial (transverse) ultrasound view of a pelvic abscess (Red dot) 
posterior to the bladder (Blue dot). 
 
Trans-Rectal Drainage of Pelvic Abscess 
Richard Davis 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
Sagittal (longitudinal) ultrasound view of the same abscess as 
above. This abscess could be palpated anterior to the rectum in 
a man, so it is clearly in the rectovesical space (“Pouch of 
Douglas”). 
 
3. Place the patient in lithiotomy position. Ideally, 
the patient’s bottom will lie a little past the end 
of the bed, and their thighs and knees will be 
retracted towards the shoulders, as shown below:  
 
The patient is in lithotomy position with the legs drawn up 
towards the shoulders. The bed is raised so that the surgeon, 
seated, can see well into the rectum. A headlight is very helpful 
for this operation.  
 
4. For abscesses adjacent to the proximal rectum 
(far from you) a circumferential retractor such as 
the one shown below will be best. For a distal 
(closer to you) abscess a standard anal speculum 
is enough. Here, we show a circumferential 
retractor. Insert it so that the open part faces 
towards where you felt the abscess on rectal 
examination.  
 
This anal retractor (Hill-Ferguson) provides circumferential 
retraction of the anus and rectum, exposing the area of interest.  
 
 
If a suitable anal retractor is not available, the double-bladed 
vaginal speculum (Sims) is common and could be an acceptable 
substitute. Source: Sarindam7, CC BY-SA 4.0 via Wikimedia 
Commons 
 
5. Palpate the abscess (which you felt before) with 
the retractor in place to confirm its location and 
accessibility. 
Trans-Rectal Drainage of Pelvic Abscess 
Richard Davis 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
Palpate the abscess to confirm its location once you are ready 
to drain it. Be careful to distinguish it from the prostate (in a 
man) which will also be firm but not fluctuant. 
 
6. Aspirate the abscess with a needle. Use one that 
is 21G or larger, as the thick pus may not pass 
through the needle. If you do not locate the 
abscess at first, be sure that the needle is not 
obstructed by blood or debris on subsequent 
attempts.  
 
Holding and directing the retractor with your non-dominant 
hand, insert the needle into the area of fluctuance that you felt 
previously.  
 
At this point, if you are planning to use a pigtail 
catheter over a guidewire to drain the abscess (as 
discussed above) pass the guidewire through the 
needle, incise along the guidewire, dilate the tract 
over the guidewire, and pass the catheter into the 
abscess cavity.  
7. Make a single incision with a #11 blade in the 
area where the pus was aspirated. Insert a finger 
through the incision to feel the inside of the 
cavity before finishing the “X” shape with a 
second incision.  
 
Make a small incision exactly where the needle inserted. Pus 
should come out, confirming proper location of the incision.  
 
8. Probe, then irrigate and aspirate the inside of the 
cavity. Use a rigid suction catheter to gently 
probe the extent of the cavity and break up any 
loculations. Then use it to irrigate and suction 
inside the cavity.  
 
Insert a suction catheter into the cavity and direct the tip 
around the inside of the abscess cavity.  
 
Trans-Rectal Drainage of Pelvic Abscess 
Richard Davis 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
A catheter-tip 60cc syringe may fit into the end of your suction: 
if so, use it to irrigate the cavity thoroughly. 
 
9. If you were able to see the abscess with the 
ultrasound preoperatively, look again to confirm 
that it is deflated.  
 
Sagittal ultrasound view of the pelvis shows complete 
resolution of the abscess, compared with the preoperative 
images above.  
 
10. Leave a drain to maintain continuity between the 
abscess cavity and the rectum. A Foley catheter 
with the balloon removed, a “mushroom” 
(Malecot) catheter, or a pigtail catheter are all 
suitable. Secure the catheter to the cut edge of the 
rectum / abscess wall using plain gut, which will 
absorb within 3-5 days allowing the catheter to 
fall out in a timely manner. Chromic gut will last 
for 2-3 weeks, and other absorbable sutures will 
last longer, so these are not good options. 
Suturing the drain to the skin adjacent to the anus 
is not a good option either, as it will inevitably 
fall out. If you do not have plain gut, consider 
suturing the drain loosely with a suture that is 
easily visible and returning after 5 days to 
remove the suture: a cooperative patient may 
tolerate this without anesthesia, with an anal 
speculum and good lighting.  
11. Put the patient on IV antibiotics and transition to 
oral ones when they are able to eat and drink. 
Continue for 5 days. If the patient has been 
hospitalized and on antibiotics previously, 
consider a drug-resistant organism. Culture the 
pus if you can and choose antibiotics according 
to your local resistance patterns.  
 
Pitfalls 
• Misidentification: Especially without a CT scan, 
you may mistake other entities that are tender or 
fluctuant for an abscess: rectal cancer, mesenteric 
duplication cyst, ovarian cyst,  
• Not contained: If the abscess does not show signs 
of maturity such as rim enhancement on imaging, 
attempting to drain it as described here would 
result in a rectal perforation that was either intra-
or extra-peritoneal. Either would be disastrous. 
We have in the past used percutaneous drainage 
or mini-laparotomy in various parts of the 
abdomen to evacuate free fluid if the patient was 
too sick for a laparotomy, but we would not 
recommend this approach for trans-rectal 
drainage.  
• Recurrence: An inadequate incision, or one that 
closes too soon, can cause this complication. 
Surgeons usually leave a drain across the incision 
site for this reason. Also inadequate probing and 
irrigation of a loculated abscess, after it has been 
entered, can leave behind a focus of undrained 
infection.  
• Inability to find the abscess after the patient is 
asleep: Unless you are 100% sure you can feel it 
Trans-Rectal Drainage of Pelvic Abscess 
Richard Davis 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
on rectal exam before anesthesia is induced, 
consent the patient for a laparotomy at the same 
time. If the patient has had a laparotomy between 
2 and 6 weeks previously, this is a very difficult 
situation. Your options include continuing to try 
to find the abscess trans-rectally with careful 
aspiration, or reopening the abdomen through a 
different incision than was used previously, such 
as a low transverse one as close to the abscess as 
you can.  
 
Richard Davis MD FACS FCS(ECSA) 
AIC Kijabe Hospital 
Kenya 
 
July 2024 
