Incomplete Evacuation of Stool

What is incomplete evacuation of stool?

It’s not uncommon to have a bowel movement, yet have the sensation that everything did not come out. When this feeling occurs regularly, it’s called tenesmus.

With tenesmus, stool isn’t actually left behind in your intestine. It just feels that way. It usually means that something is affecting your rectum (the part of the colon by your anus). Causes of tenesmus include irritable bowel syndrome or ulcerative colitis.

In some cases, you may actually have stool left behind (incomplete evacuation of stool). This happens when your anal and pelvic muscles do not coordinate well to allow stool to exit your body.

Treatment of tenesmus or incomplete evacuation of stool depends on the underlying cause.

Causes

1. Irritable bowel syndrome

Symptoms

• Belly pain more than once a week, often related to bowel movements.
• Diarrhea, constipation, or a mix of both.
• Stool becomes frequent (more than 3 times a day) or less frequent (less than 3 times a week).
• Feeling like there is stool remaining, even after straining to have a bowel movement.

Irritable bowel syndrome (IBS) is a common, chronic disorder of the large intestine that causes changes in your bowel movements and abdominal pain.

There are subtypes of IBS: You can have primarily diarrhea, primarily constipation, or both. All forms cause abdominal pain at least once a week. IBS is more common in women, people under 50, and people with mental health issues (particularly depression and anxiety.)

IBS is a chronic disease, meaning that symptoms last for months or years. Symptoms usually come and go over time. Stress often worsens symptoms.

Treatment can involve several different approaches. You may need to change your diet if any foods or drinks trigger your symptoms. Your doctor may recommend fiber supplements, regular exercise, and ways to manage life stressors (including getting enough sleep). There are also several prescription medications that can help with your symptoms.

2. Constipation from functional outlet obstruction

Symptoms

• Trouble pushing stool out of the anus
• Trouble starting or finishing a poop
• A feeling that you did not get all your stool out after a bowel movement (incomplete evacuation)
• Less than three bowel movements a week

Constipation is when you have trouble passing stool. One type of constipation involves difficulty pushing the stool out. Your pelvic muscles have trouble coordinating the muscles movements, resulting in a functional outlet obstruction. This is also called dyssynergic defecation or pelvic floor dyssynergia.

You will be referred to a gastroenterologist (digestive disease specialist) who can diagnose you. They will use a special probe (manometry) or inflated balloon to measure your ability to push out stool.

Treatment of constipation from functional outlet obstruction involves biofeedback training. Your doctor will send you to a special type of therapist who will use techniques to teach your pelvic muscles to work together to have a bowel movement. They may also have you stick to a specific schedule to try having bowel movements—called “habit training”.

3. Ulcerative colitis

Symptoms

• Crampy abdominal pain
• Frequent bloody diarrhea—may wake you up at night
• Urgent need to have bowel movements, often with very little warning
• Feeling that you still need to pass stool, even after you have had a bowel movement
• Fever
• Weight loss

Ulcerative colitis (UC) is a form of inflammatory bowel disease (IBD). The lining of your large intestine (colon) and rectum become inflamed and develop tiny, open sores, called ulcers. UC is caused by abnormal immune system activity primarily in your large intestine. Diagnosis is usually done by a colonoscopy and a biopsy of the intestinal wall.

UC is chronic and develops over time. It has episodes of severe symptoms or “flares.” Sometimes with severe rectal inflammation, you can get a sensation that you need to pass stool, even after you just had a bowel movement (tenesmus).

There are many treatment options, including pills and medications that are injected (through an IV or under your skin.) You may also use suppository creams or sprays.

Although there is no cure, the goal of treatment is to cause it to go into “remission”, meaning you don’t have symptoms and the intestinal lining can heal. If medications are not successful in inducing remission, you may require surgery to remove your large intestine.

UC increases your risk for colon cancer, and it is important that you are treated and followed up by a gastroenterologist.

Other possible causes

Several other conditions may also cause a sensation of incomplete evacuation of stool, though these are either much less common or the sensation is not usually a main symptom. They include hemorrhoids, cancer, certain GI infections, and Crohn's disease.

When to call the doctor

If you have a persistent feeling of incomplete evacuation, call your doctor. This could be a sign of a more serious condition like IBD or colon cancer. Depending on your symptoms, they may refer you to a gastroenterologist for further testing.

Incomplete evacuation of stool will almost never require a trip to the ER.

Treatments

At-home care

Though treatments often depend on the cause, some approaches that may help alleviate your symptoms include:

• Fiber supplements
• Laxatives
• Over-the-counter pain medications for the abdominal pain and cramping

Other treatment options

If your incomplete evacuation of stool is caused by an underlying condition, your doctor may prescribe different medications. Options include:

• For IBS: medications with laxative effect such as linaclotide (Linzess).
• For UC: steroids (oral or intravenous), immunosuppressants such as azathioprine (a pill), biologic medications such as infliximab (Remicade, given intravenously), or medications delivered rectally like mesalamine enema (Rowasa).