This sounds paradoxical, but it happens more often than people realize.
I love sharing this with patients. In severe constipation, hard stool becomes stuck in the rectum or colon. Liquid stool from higher up in the intestine can then leak around the obstruction, producing loose stools or even explosive diarrhea. Clinically, this is called overflow diarrhea. Sometimes this is even interpreted as fecal incontinence— yes, people are worried that they’re pooping their pants because of the ‘stool leakage’. However, with a little bit of history-taking and physical exam, we can generally rule out true fecal incontinence due to anal sphincter dysfunction.
Overflow diarrhea is most common in:
chronic constipation
older adults
patients on opioids or constipating medications
severe stool impaction
“I can’t be constipated — I have diarrhea.”
But imaging or examination reveals the colon is actually packed with stool.
Treating the diarrhea alone won’t fix the problem. The underlying impaction or constipation must be relieved first.
Clues that diarrhea might actually be constipation include:
alternating constipation and loose stool
small frequent stools
abdominal bloating or distention
feeling incompletely empty after bowel movements
Once the retained stool is cleared, the “diarrhea” usually resolves.
Treatment for overflow diarrhea generally depends on the underlying diagnosis. This may involve clearing out the fecal impaction from the bottom up with enemas or suppositories, or doing a manual disimpaction, which can be done awake or asleep in the operating room, with either gloved hands or a scope of some sort. We have many tools.
If there is any suspicion of true fecal incontinence, anal manometry (a test of sphincter tone and nerve function) may be required.
But overall, now that you know it exists, does this kind of explain your symptoms better?
Learn More: Lets Talk About Diarrhea!
