Fecal Impaction
A hardened mass of stool stuck in the bowel
Quick Facts
- Type: Severe complication of constipation
- Cause: Hard, dry stool that cannot pass
- Common in: Older adults, bedbound, certain medications
- Warning: Severe pain, vomiting, or no stool/gas needs urgent care
Overview
Fecal impaction is a buildup of hardened, dry stool that becomes lodged in the rectum or lower colon and cannot be passed on its own. It usually develops as a complication of chronic constipation, when stool sits in the bowel long enough for the body to absorb its water, leaving a hard mass.
The condition is most common in older adults, people who are bedbound or have limited mobility, and those taking certain medications such as opioids. It can be uncomfortable and, if left untreated, may lead to complications. A confusing feature is that liquid stool can sometimes leak around the blockage, which may be mistaken for diarrhea. Fecal impaction is generally treatable, but a severe blockage with significant pain or vomiting can be a medical emergency.
Symptoms
Symptoms reflect both the blockage and the body's response to it:
- Constipation that does not respond to usual measures, with infrequent or no bowel movements
- A feeling of fullness or pressure in the rectum and an urge to pass stool without success
- Abdominal pain, cramping, and bloating
- Leakage of watery or loose stool around the hard mass, which can look like diarrhea or cause soiling
- Nausea, loss of appetite, and sometimes vomiting
- Rectal discomfort or bleeding
In older or frail people, fecal impaction can also cause confusion, restlessness, or a general decline. Severe pain, vomiting, a swollen tender abdomen, or inability to pass any stool or gas needs urgent care.
Causes
Fecal impaction almost always results from prolonged constipation, with several contributing causes:
- Chronic constipation: Stool remains in the colon too long and dries out.
- Medications: Opioid painkillers, some antidepressants, iron supplements, and certain other drugs slow the bowel.
- Low fiber and fluid intake: A diet lacking fiber and not enough water.
- Reduced mobility: Being bedbound or inactive slows bowel movements.
- Other conditions: Nerve or muscle disorders affecting the bowel, an underactive thyroid, and ignoring the urge to defecate.
Risk Factors
- Older age
- Long-term use of opioid pain medication
- A history of chronic constipation
- Limited mobility or being bedridden
- Low-fiber diet and inadequate fluids
- Neurological conditions, spinal cord problems, or an underactive thyroid
- Frequent use of certain laxatives or ignoring the urge to go
Diagnosis
Doctors diagnose fecal impaction from the history and examination:
- Digital rectal exam: A gloved finger inserted into the rectum can detect a hard stool mass.
- Abdominal examination: Checking for distension, tenderness, and a palpable mass.
- Imaging: An abdominal X-ray can show stool buildup and help assess the extent of the impaction or any obstruction.
Doctors also look for underlying causes and rule out a true bowel obstruction or other serious abdominal conditions.
Treatment
Treatment aims to clear the impacted stool and then prevent it from returning:
- Enemas and suppositories: To soften and help expel the stool from the rectum.
- Manual disimpaction: A clinician may gently break up and remove the hard stool by hand when needed.
- Oral laxatives: Used to clear remaining stool higher up, often after the rectum is cleared.
- Ongoing bowel regimen: After clearing, a plan of fiber, fluids, stool softeners, and scheduled laxatives helps prevent recurrence.
Treatment should be guided by a clinician, especially in older or medically fragile people, and underlying causes such as medication side effects should be addressed.
Prevention
- Eat enough fiber from fruits, vegetables, and whole grains
- Drink adequate fluids
- Stay as physically active as possible
- Do not ignore the urge to have a bowel movement
- Review constipating medications with your doctor, especially opioids
- Use prescribed stool softeners or laxatives proactively if you are prone to constipation
When to See a Doctor
See a doctor if you have constipation that will not clear, a feeling of blockage, or leakage of liquid stool around hard stool. Seek emergency care immediately if you have:
- Severe abdominal pain or a swollen, tender abdomen
- Vomiting, especially if it looks like stool
- Inability to pass any stool or gas
- Rectal bleeding, fever, or signs of feeling very unwell
These can signal a bowel obstruction or other serious complication that needs urgent treatment.
Frequently Asked Questions
What is fecal impaction?
It is a large, hard mass of dry stool that becomes stuck in the rectum or colon and cannot be passed normally. It usually develops from long-standing constipation when stool sits in the bowel and loses its water. It is most common in older adults and people on opioid medications.
Why does liquid stool leak with fecal impaction?
Watery stool from higher in the bowel can seep around the hard, stuck mass and leak out, which is often mistaken for diarrhea. This overflow leakage is actually a sign of blockage, not loose bowels, and the underlying impaction still needs to be treated.
How is fecal impaction treated?
Treatment usually starts with enemas or suppositories to soften and clear the stool, and a clinician may need to gently remove the hardened mass by hand. Oral laxatives clear remaining stool, followed by an ongoing plan of fiber, fluids, and laxatives to prevent it returning.
Who is at risk for fecal impaction?
Older adults, people who are bedbound or inactive, and those taking opioid pain medications are most at risk. A low-fiber diet, inadequate fluids, chronic constipation, and certain neurological or thyroid conditions also increase the risk. Addressing these factors helps prevent it.
When is fecal impaction an emergency?
Seek emergency care for severe abdominal pain, a swollen or tender abdomen, vomiting (especially if it looks like stool), inability to pass any stool or gas, or rectal bleeding with fever. These can indicate a bowel obstruction or other serious complication needing urgent treatment.
References
- MedlinePlus, U.S. National Library of Medicine. Fecal impaction.
- National Institute on Aging. Concerned about constipation?
- Mayo Clinic. Constipation — Symptoms and causes.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).