My friend has frightful constipation. I’ll call her X because she’s embarrassed by it. She staggered to the chemist and asked to speak to the pharmacist. “You can tell me what’s wrong,” said the assistant. “He’s out the back. I’ll tell him.”

“Constipation,” whispered my friend.

“This lady needs something for constipation!” roared the assistant, alerting crowds of customers and shaming poor X. But why be ashamed? It is no fun to feel clogged up with cement, so uncomfortable that your bottom is always on your mind. This is a nasty illness – painful, depressing and, if not dealt with, it can kill you. The incontinence lady came to visit my mother decades ago and told us all about it. This was a tremendous relief for my mother – mentally if not physically – because she longed to talk about it in detail, but hardly anyone would ever listen, never mind chat about it – except me, her captive audience. Now here was a heavenly, sympathetic expert with thrilling bowel stories to tell.

“It can back up to here!” said the incontinence lady, pointing to the middle of her chest. We screamed in unison and vowed to drink litres of water daily until the end. But, sadly, it is only in such select company that we can have shrieks and laughs at bowel function: blocks, squits, farts, bloats and stinks. If only X had been with us because she has only ever faced revulsion or mockery.

There is little equality in this area. There should be; it’s not gender-specific. But only chaps may laugh and shout about it; women may not, sometimes not even among themselves. And we need to, when faced with intense discomfort and possible death. “Do not strain at stools,” Rosemary’s heart-failure-clinic nurse warned her, or you might peg out, like George II, Elvis and (probably) Evelyn Waugh, from fatal heart arrhythmia.

We can mention breastfeeding and period stains out loud without shame. Now let’s, please, add constipation. Because the older you get, the more likely you are to have it. So chill out and loosen up. At least at the top end.

• Michele Hanson is a Guardian columnist