Paradoxical (Overflow) Diarrhea: Causes, Treatment, More

Paradoxical diarrhea, or overflow diarrhea, is when you have constipation and diarrhea at the same time. It happens when watery stool leaks around a fecal impaction (hardened piece of stool stuck in the colon).

Paradoxical diarrhea often occurs when you have been experiencing constipation for a while. You may also have symptoms like stomach pain and bloody stool. Treatment methods focus on alleviating constipation and restoring normal bowel movements.

You may experience paradoxical diarrhea after several days of constipation. Constipation, generally defined as having less than three bowel movements per week, commonly includes the following symptoms:

• Hard or dry stools that are difficult to pass
• Straining or inability to have a bowel movement
• Feeling like you haven’t completely emptied your bowels

From there, the main symptom of paradoxical diarrhea is experiencing episodes of diarrhea (watery, liquid stool). Other symptoms may include:

• Stomach pain or cramping
• Nausea
• Bloating
• Rectal pain
• Bloody stool

Paradoxical diarrhea occurs when watery stool leaks around a fecal impaction (a hard piece of poop that is stuck in the digestive tract).

It’s often triggered by chronic (long-term) or severe constipation. When you don’t pass stool for a long time, hardened stools can accumulate and become stuck in the colon, a condition known as a fecal impaction.

When you have constipation for an extended period, the muscles in your rectum may also stretch and weaken. These factors can lead to the release of overflow diarrhea, as watery stools have built up behind the stool blockage.

You might be more likely to experience paradoxical diarrhea if you have irritable bowel syndrome with mixed bowel habits (IBS-M). With this gastrointestinal (GI) disorder, it’s common to experience episodes of constipation and diarrhea that periodically alternate. Researchers aren’t entirely sure what causes IBS-M, but an imbalance in the gut microbiome may lead to issues with the gut-brain axis, which can disrupt bowel habits.

Paradoxical diarrhea isn’t considered rare, but it may be initially overlooked or misdiagnosed.

To confirm that you’re experiencing paradoxical diarrhea, a healthcare provider will ask about your medical history and current bowel movement-related symptoms. They may perform or order the following diagnostic tests, including:

• Physical exam: A healthcare provider will examine your body for visible or noticeable symptoms, such as bloating or stomach pain. For example, they may gently press on your stomach area to see if you feel abnormal pain.
• Digital rectal exam: A healthcare provider will insert a gloved finger into your rectum to manually detect a hardened piece of impacted stool.
• Imaging tests: An abdominal X-ray or computed tomography (CT) scan can provide images of the inner abdomen to identify any impacted stool in the digestive tract or rule out other potential concerns.
• Barium enema: Injecting barium (a type of contrast dye) into the colon through an enema allows a healthcare provider to view blockages in the digestive tract more easily during imaging tests.

The goal of treating paradoxical diarrhea is to manage and improve your bowel habits to reduce the risk of constipation or diarrhea. A treatment plan may include:

• Enemas: Using warm tap water or other liquid solutions, an enema (a small tube that directs liquid directly into your colon) can help break up and release hardened stool. You may need more than one enema to resolve symptoms.
• Manual removal of fecal impaction: A healthcare provider may need to manually remove any stubborn pieces of hard poop that remain stuck. This involves carefully inserting a gloved finger into the rectum and breaking up the lump of stool into smaller pieces so that they can be removed.
• Laxatives: Medications or natural remedies that help you have a bowel movement may help clear a hardened piece of poop, under the guidance of a healthcare provider.

While it may seem appropriate to treat watery stool with anti-diarrheal medications, this may make paradoxical diarrhea worse. In this case, opt for over-the-counter (OTC) anti-diarrheal medications like Imodium (loperamide) or Pepto-Bismol (bismuth subsalicylate) if suggested by your healthcare provider.

Preventing paradoxical diarrhea generally involves maintaining healthy bowel habits and avoiding constipation. Here are some dietary and lifestyle tips:

• Eat more high-fiber foods: Fruits, vegetables, and grains are high in fiber, which can help bulk up stool and promote regular bowel movements.
• Stay hydrated: This can help prevent stool from becoming hard and help it move through your digestive tract.
• Get enough exercise: Daily physical activity, like brisk walking, can help stimulate your digestive tract, preventing constipation.
• Make time for regular bowel movements: When you feel the need to go, use the bathroom without rushing. You can also try “training” your poop schedule by making time for the bathroom at the same time each day.
• Review your current medications: Discuss your current medications with a healthcare provider to determine if any of them include constipation as a side effect. They may be able to suggest an alternative drug.

If left untreated, paradoxical diarrhea may come with some potential complications.

Both chronic constipation and diarrhea can lead to fecal incontinence. This occurs when the muscles in your rectum and anus weaken and cannot hold in stool, leading to accidental bowel leakage.

Experiencing long-term diarrhea can also cause dehydration. This can be especially serious for older adults and people with weakened immune systems.

Paradoxical diarrhea—experiencing diarrhea while constipated—happens when watery stool overflows around a hardened piece of poop that’s stuck in the colon. It usually occurs when you have long-term constipation or as a result of a type of irritable bowel syndrome (IBS).

Treating paradoxical diarrhea involves removing the stool blockage, restoring regular bowel movements, and preventing further episodes of constipation. If you think you may have paradoxical diarrhea, a healthcare provider can help provide a diagnosis and recommend a treatment plan.