Constipation happens when stool is dry and difficult to pass, resulting in three or fewer bowel movements a week.

Overactive bladder (OAB) causes urinary urgency, or frequent and sudden urges to pee. It’s caused by a problem with bladder function.

Constipation and OAB often appear together. That’s because constipation increases the risk of OAB, and vice versa.

When constipation and overactive bladder occur at the same time, it’s known as bladder and bowel dysfunction (BBD).

Read on to learn about the link between constipation and OAB, plus when you should see a doctor.

There are two types of OAB: dry and wet.

Dry OAB is an overactive bladder without urinary incontinence, which is the inability to control urination.

Wet OAB is an overactive bladder with urinary incontinence. This typically occurs right after you feel the urge to pee. It can cause leaking.

The other symptoms of dry and wet OAB are the same. Both types of OAB cause:

  • sudden urges to urinate (urinary urgency)
  • urinating at least eight times every day
  • urinating at least two times every night (nocturia)

Constipation is characterized by dry, hard stool that’s difficult to pass.

Typically, constipation develops when the stool stays in the large intestine (colon) for too long. That’s because the body reabsorbs water from the stool. So, the longer it stays in the colon, the drier it gets.

This can also happen if the stool travels through the colon at a slow rate.

Additionally, as stool continues to stay in the colon, it can build up. This can further worsen constipation.

Constipation is usually a symptom of another condition, rather than a disease itself. It can also happen without a specific cause.

Symptoms of constipation

Common constipation symptoms include:

  • having less than three bowel movements each week
  • hard, dry, or lumpy stools
  • straining to pass stool
  • a feeling of fullness, even after passing stool
  • pain during bowel movements

Constipation can lead to OAB and urinary urgency.

This is due to the buildup of stool in the colon during constipation. According to a 2021 study, the accumulation of stool puts pressure on the bladder. The bladder, which stores urine, is located near the rectum.

The physical pressure of the stool also constricts the urethra. This is the tube that lets urine move out of the body. As a result, it becomes difficult for the body to hold urine, leading to urinary urgency and incontinence.

A 2017 study also found that functional constipation, or constipation without a specific cause, can lead to wet OAB. It’s also related to moderate to severe OAB.

Similarly, another 2021 study found that constipation increases the risk of urinary urgency. The researchers noted that the constant straining in constipation can weaken the pelvic floor muscles, leading to urinary problems.

According to a 2016 study, some aspects of OAB can lead to constipation.

For example, when experiencing urinary urgency, you might contract your urethra to hold in pee. This can prevent proper functioning of the anal sphincter, which is responsible for releasing stool.

Additionally, if you have urinary urgency, you might delay trips to the bathroom. In doing so, you may hold in bowel movements, which increases the risk of dried stool and constipation.

In some cases, OAB can indirectly cause constipation. If you have urinary urgency, you might be prescribed medication that relaxes your bladder muscle. This medication can also relax the gut, resulting in slow-moving stool and constipation.

Some people are more likely to experience constipation and overactive bladder.

This includes:

It’s normal to experience occasional episodes of constipation or urinary urgency.

However, you should visit a doctor if you have:

Constipation and overactive bladder can be related. In constipation, the buildup of stool in the colon places pressure on the bladder. This makes it difficult for the bladder to hold pee, resulting in urinary urgency and OAB.

Likewise, in OAB, you might avoid the bathroom or contract your urethra to hold in pee. This can keep stool in your colon longer, increasing the risk of constipation.

Most cases of constipation and urinary urgency are temporary. But if you experience frequent symptoms, see a doctor.