What Are The Signs Of A Perforated Bowel After A Colonoscopy?

The Main Signs of a perforated bowel after colonoscopy are sudden severe abdominal pain, tenderness, and localized or diffuse abdominal swelling. Also, fever, bloody stool and low blood pressure can occur.

1- Sudden severe abdominal pain.


It is normal to feel some colicky pain or discomfort after a colonoscopy. Not every pain you feel is because of bowel perforation (ref).

The abdominal pain caused by bowel perforation during colonoscopy is different. today, I will explain the differences in-depth.

Bowel perforation because of colonoscopy can be felt during colonoscopy or soon after you recover from anesthesia.

Sudden severe abdominal pain is the major sign of a perforated bowel after colonoscopy.

In an in-depth discussion about the causes of stomach pain after colonoscopy, Read HERE.

How does the bowel perforation pain feel like?

The pain is usually acute, and more extreme (unlike the usual gas pain or discomfort you may feel after colonoscopy).

The pain is steady or increasing, continuous, and agonizing (not crampy as the usual gas pains after colonoscopy).

Perforation pain is usually associated with severe tenderness in touch. This occurs usually all over the abdomen, but maximum over the site of perforation.

When you will start experiencing colon perforation pain?


The time you will start feeling the pain due to perforation varies according to the type of sedation or anesthesia with colonoscopy.

With colonoscopy, your doctor may offer (ref):

  • Without sedation at all: very few people choose this, you will immediately feel severe pain at the site of perforation.
  • With light sedation to moderate sedation: although you’re sleepy, you are aware and can obey commands. Also, you will feel great pain during the procedure of colonoscopy.
  • With deep sedation: This is deeper but you can still respond to painful stimuli, but the response is unpurposeful as your consciousness and memory are impaired with deep sedation. you will soon feed the pain after the sedation ceases.
  • General anesthesia: With general anesthesia, you are not able to feel or respond to pain during colonoscopy. the pain will start after recovery from anesthesia (after the colonoscopy procedure).

People report abdominal pain within the first 24 hours after colonoscopy. Others may seek medical help after 24 hours.

Actually, 25% of patients with bowel perforation after colonoscopy have a delay in seeking medical help. And this can result in complications (ref).

What is the Common site of Bowel perforation pain with colonoscopy?


The colonoscopy procedure involves only your large intestine and the last few centimeters of the small intestine.

The perforation from colonoscopy occurs in the large intestine. A colonoscopy usually doesn’t cause small intestinal, duodenal, gastric, or esophageal perforation.

Pain starts in the abdominal area over the site of perforation and rapidly spreads all over the abdomen.

The most common sites of perforation by colonoscopy are (ref):

  • Rectum and sigmoid colon {53%}: Starts as lower left abdominal pain and then becomes generalized.
  • Cecum {24%}: starts as lower right abdominal pain and soon becomes generalized all over the abdomen.
  • Ascending colon {9%}: Starts on the right side of your abdomen, and spreads.
  • Transverse colon:  {9%}: starts at the upper part of your abdomen as abdominal pain under ribs, or chest pain.
  • Descending colon {5%}: Starts as left-sided abdominal pain.

2- Blood in stool.

The presence of blood in stool after colonoscopy can be a normal finding (ref). This usually occurs due to:

  • Manipulations during colonoscopy can lead to mild trauma inside the colon (without perforation).
  • Certain procedures by the colonoscopist: common procedures causing blood in stool are removal of a polyp or taking a biopsy.
  • lesion inside your colon such as an ulcerated polyp may bleed after colonoscopy.

However, perforation can also lead to red or dark blood in the stool. especially if the perforation is in the last part of the colon or in the rectum.

It is not a role to bleed with every bowel perforation. so bleeding per rectum can occur but is not a cardinal sign of perforated bowels.

Unfortunately, the amount of bleeding is not relevant to the extent of the damage. You can bleed more with polyp removal than from a bowel perforation.

What raises the suspicion:

  • Bleeding large amounts of blood without a history of procedures during the colonoscopy (such as removing a polyp or taking a biopsy).
  • the onset of bleeding is associated with the sudden severe pain of the perforation ( as I described above).
  • Bleeding that is not going away.

A small transient bleeding per rectum after colonoscopy without significant abdominal pain can occur normally.

3- Rigid, tender abdomen.

What sets the pain from the bowel perforation apart is its association with severe tenderness in your abdomen (ref).

A rigid, tender abdomen with a great spike of pain on the pressure on the affected area is suggestive of bowel perforation.

The tenderness is maximum over the area of perforation, but it expands to the whole abdomen.

Tenderness occurs even with a slight movement, walking, or bending of your body.

Normally, you may feel some tenderness over your after colonoscopy. but it is milder in severity, not related to movement as with bowel perforation.

Learn more about the Warning Signs of abdominal pain after colonoscopy.

Also, abdominal tenderness due to bowel perforation is usually associated with severe sharp pain, nausea, vomiting, and maybe fever.


4- Bloating or localized swelling (mass) in your abdomen.

Again, bloating can occur normally after colonoscopy (the most common symptom after colonoscopy).

stomach pain after colonoscopy


Most people feel bloated after colonoscopy as your doctor uses air to inflate your colon during the procedure.

Residual air can cause some cramps and bloating sensations as a part of normal post-colonoscopy symptoms.

However, severe bloating or localized swelling of your abdomen that is not going away for hours can occur with bowel perforation (ref).

The bloating is usually associated with severe sharp abdominal pain, abdominal tenderness, nausea, or vomiting.

The presence of bloating without other acute severe symptoms of bowel perforation doesn’t suggest bowel perforation. You don’t have to worry as bloating alone is not a sign of bowel perforation.

5- Fever, Chills, or low body temperature.

As a result of bowel perforation, feces, and waste products escape to the outside of the colon. These products can cause inflammation of the lining tissue layer of the abdomen (called the peritoneum).

Not only this but also, these septic products can reach the blood circulation and cause infection and sepsis.

This contamination of the inner tissues and blood with contents from the perforated colon trigger inflammation with chills and fever.

So, the presence of fever or chills after colonoscopy is a warning sign of intestinal perforation. especially if the fever is associated with other signs of a perforated bowel.

However, Some patients may experiences fever after colonoscopy for other reasons than perforation as:

  • Few bacteria may leak into the blood without colon perforation or polypectomy (Transient bacteremia).
  • Transient bacteremia after removal of a colon polyp (Polypectomy).
  • some anesthetic medications (especially with general anesthesia).

Also, in some cases where the perforation is associated with severe sepsis (especially if left undiagnosed), hypothermia may occur (ref).

MORE: general ill feeling after colonoscopy.

6- Severe nausea or vomiting.

Severe nausea or even vomiting usually occurs with bowel perforation after colonoscopy.

This is because of the severe pain or the leakage of colon contents into the peritoneum causing its inflammation (peritonitis).

Mild nausea or vomiting can occur normally after the colonoscopy due to:

  • effects of the pre-colonoscopy preparations.
  • severe gas distension.
  • as a result of sedation or anesthetic mediation.

If nausea and vomiting are associated with severe pain and tenderness, you have to seek medical help.


7- Signs of low blood pressure (septic shock).

leakage of stomach contents into the peritoneum and blood may cause a severe form of infection called septic shock.

As a result, the presence of bacteria and its toxins inside the blood circulation will cause the blood circulation to collapse and cause low blood pressure.


Symptoms of shock (low blood pressure) include:

  • Dizziness, lightheadedness, confusion, or even coma.
  • Restlessness and agitation.
  • Cool, pale arms or legs.
  • Shortness of breath, rapid breathing.
  • Rapid heartbeats (palpitations).
  • Very high or very low body temperature
  • Chills.
  • Little or no urine.
  • Nausea, lack of appetite.

Learn more about septic shock



8- No symptoms!

In rare cases, colon perforation can occur without any symptoms, this is more obvious with (ref):

  • people undergoing colonoscopy for diverticulosis.
  • Very old age.
  • People with extremely bad health conditions or very low immunity as with chemotherapy patients.
  • Tiny perforations can heal spontaneously.


How your doctor can detect a perforated bowel after a Colonoscopy?


IF you suspect any signs of bowel perforation after colonoscopy, you have to rush into the emergency room.

Here are what to expect from your doctor or gastroenterologist:

  • Your doctor will take a detailed history of all the details of the post-colonoscopy condition and symptoms you feel.
  • Perform a detailed abdominal examination, check your vital signs, and he may perform a rectal examination.
  • Your doctor may order some lab tests such as a complete blood picture, renal function test, urine sample, C reactive Protein…
  • plain X-ray on your abdomen in the erect position can diagnose colon perforation.
  • Also, abdominal Ultrasonography, C.T, or MRI can be done to confirm the condition.
  • Your doctor may prepare you for surgery, another colonoscopy. or admit you for treatment and observation at the hospital.

Learn more here.