Proctalgia fugax: The ‘lightning pain’ in the butt you might've felt while on your period and probably ignored

You’re sitting at your desk, your legs crossed, fielding work requests and generally minding your own business when it hits – a sharp pain in the pelvic area. It seizes you for a second – maybe more – and then it’s gone, and your lower body relaxes again. 

Sound at all familiar?  

WHAT IS PROCTALGIA FUGAX?

This condition – known as proctalgia fugax – affects one in eight people, with women experiencing it more than men, said obstetrician and gynaecologist Dr Tan Toh Lick.

“It is an episodic sharp fleeting pain in the anus or lower rectum, (which) can be triggered during menstruation,” he said.

Professor Francis Seow-Choen, a colorectal surgeon, said that the pain – essentially a muscle spasm – is “very common”.

For many people, it lasts only a few seconds, earning it the moniker “lightning pain”, but it can also last minutes and for some, hours, he said.

Some clients at women-focused Orchard Clinic have even described the pain as being “worse than childbirth”, said its co-founder and principal consultant Cheryl Han.  

As for frequency, “some people experience recurring episodes while others might only feel it once or twice in their lifetime”, said Prof Seow-Choen.

Besides menstruation, proctalgia fugax can also occur in people who suffer from stress or constipation, as well as be triggered by bowel movements and sexual activity, Dr Tan said.

The cause of this is “unclear”, said Dr Tan, but “anal muscle spasm is implicated”.

“The chemicals suspected to cause period pain by affecting the muscle and blood vessels of the womb can also affect that of the rectum and pelvic floor, causing cramps,” Dr Tan said, adding that rectal cramping in women may be followed by painful menstruation, usually in the first few days.

For Prof Seow-Choen, it could be a matter of the brain firing impulses to the wrong part of the body.  

“If you’re menstruating, the brain may get signals from the uterus but fire wrongly to the rectum. It’s like when your phone gets cross-wired and you can hear someone else’s conversation. Theoretically, I think that’s possible,” he said.

Those who are stressed out or very anxious can also trigger the brain to fire impulses to parts of the body, he added.

YOU'VE HAD RECTAL CRAMPS. SHOULD YOU SEE A DOCTOR?

According to Dr Tan, most women experience mild pelvic cramps. About one in six find that their cramps are “significantly severe and affect their quality of life”.

Many do not report symptoms as they think this is “normal menstruation”, said the Thomson Medical Clinic (Jurong) doctor, adding that typically, pelvic cramps during menstruation are “transient” and do not require treatment.

In fact, experts told CNA Women they rarely heard about the symptom from their own patients and clients.

Han said the topic only occasionally comes up when a client has pelvic floor dysfunction, which is characterised by an inability to relax or coordinate muscles in the area.

“There is little written about it,” said Prof Seow-Choen, adding that a lot of what doctors know about proctalgia fugax today is anecdotal.

It is recommended, however, that you see a medical professional so that other, more serious illnesses, can be excluded.

For example, your rectal cramps could be not simply due to proctalgia fugax, but symptoms of endometriosis, haemorrhoids, rectal abscess (collection of pus caused by clogged glands), anal fissure, rectocele (vaginal or rectal prolapse) or malignant disease, said Dr Tan. 

To exclude such conditions, doctors typically study a patient’s menstrual and gastrointestinal history, carry out a physical examination of the perineum and conduct tests such as a pelvic ultrasound scan, hysteroscopy (to examine the inside of the womb) and laparoscopy, he said.

PERIOD PAIN RELIEF: BREATHE AND STRETCH

“Usually, these cramps are transient and do not need treatment. However, painkillers such as mefenamic acid and paracetamol can be used,” said Dr Tan

If you're taking oral contraceptive pills or using contraceptive patches, these may also aid in relieving pelvic cramps, he added.

But for Prof Seow-Choen, the most effective way of dealing with proctalgia fugax is a bit of physiotherapy focusing on the muscle called puborectalis, concerned with “elevating the anus”.

“When that muscle contracts, it pulls the rectum forward. I teach my patients how to stretch that muscle by putting a (gloved) finger into the rectum so you can feel the anus around your finger. Then you pull gently backwards. When you do this, the muscle relaxes,” he said.

Patients can do this on their own or with the help of the doctor, said Prof Seow-Choen, who is the medical director at Seow-Choen Colorectal Surgery Centre.

“It’s not painful. And in fact, (my patients say) they feel much better and their symptoms don’t reappear.”

Physiotherapy may also be carried out on patients whose proctalgia fugax is linked to problems with the pelvic floor.

“Many people with a tense and hypertonic (overactive) pelvic floor experience concerns such as pelvic pain, said Han from Orchard Clinic.

“We would recommend a programme that includes strengthening and stimulating the pelvic floor through high-intensity electromagnetic therapy and floorwork exercises,” she said.

And if you suffer from a hypertonic or overactive pelvic floor, “learning how to breathe” will help you relax it as well as the nervous system, she added.