Lower Left Belly Pain Doesn't Mean You Have to Give Up Nuts

For years, your aunt has picked the seeds out of her strawberries and passed on the popcorn at movie night, because a doctor told her to when a colonoscopy found small pouches in her colon. She has followed that rule faithfully for years, and it never had good evidence behind it.

Pouches in the colon wall are one of the most common digestive findings in older Canadians, and when they flare, the usual first sign is lower left belly pain. What you eat does matter for those pouches, though in almost the opposite way people were told. This guide explains what the pouches are, why the old food rules stuck, and what a sensible diverticulitis diet looks like today.

Key takeaways

Up to half of people over 60 have small pouches in the colon wall, and most never have symptoms.

Between 10 and 25 percent of people with pouches go on to have a flare, when one or more pouches become inflamed or infected.

Large studies of about 47,000 men and about 30,000 women found that eating nuts, seeds, corn, or popcorn did not raise the risk of a flare.

A low-fibre diet is a known risk factor, so the long-term goal is more fibre, added slowly with plenty of water.

Belly pain with a fever needs a same-day visit, and severe pain, vomiting, or blood in your stool needs emergency care.

What does it mean to have pouches in the colon?

Having pouches in the colon means that small sacs have bulged outward through weak spots in the wall of your large intestine. Doctors call the pouches diverticula, and they use the word diverticulosis for having them without any symptoms. They become more common with age, and according to a Canadian review of the research, up to half of people over 60 have them.

Most people only learn about their pouches because a colonoscopy or a scan done for another reason happens to spot them. When one or more pouches become inflamed or infected, the condition gets a new name, diverticulitis. The GI Society's patient guide, produced with the Canadian Society of Intestinal Research, puts the share of people with pouches who go on to have a flare at between 10 and 25 percent.

So if a report says you have pouches, it does not mean you have an infection or that one is coming. It means you carry a common finding, and it gives you a good reason to pay attention to the everyday habits that keep those pouches calm.

Is belly tenderness on the left side a sign of a flare?

The classic sign of a flare is lower left belly pain that comes on and stays, sometimes mild at first and building over hours or days. That belly tenderness is easy to notice, since the spot often hurts when you press on it. Many people also run a fever, feel sick to their stomach, or notice a change in their bowel habits, which can mean constipation or diarrhea.

Those symptoms overlap with plenty of other problems, from a stomach bug to a urinary infection to trouble with other organs, such as the gallbladder pain described in our guide to right side pain after eating. Belly pain that eases after a bowel movement and keeps returning can also point elsewhere, as our article on stomach pain and diarrhea that keep coming back explains. A doctor will usually examine your abdomen and may order blood work or a scan to confirm what is going on.

Do nuts and popcorn really trigger a flare?

For decades, the standard advice for people with pouches was to avoid nuts and popcorn, along with seeds and corn. The theory made intuitive sense, since small, hard bits of food might lodge inside a pouch, irritate it, and set off an infection. Doctors, relatives, and friends repeated it so often that many people still treat it as settled fact.

When researchers finally tested the idea, it fell apart. A large study published in JAMA in 2008 followed about 47,000 men for 18 years and found that eating nuts, corn, or popcorn did not raise their risk of a flare. The men who ate popcorn at least twice a week actually had a lower risk than those who rarely ate it, and nuts showed a similar trend.

That first study left women out, even though flares become more common in women than in men after 50. In 2025, a study of nearly 30,000 women in the Annals of Internal Medicine closed that gap. The women who ate the most nuts, seeds, and fruit with seeds were at no higher risk than those who ate the least.

Each of the old rules has been tested, and none held up as a long-term way to eat.

Why did people stay on a low-fibre diet for years?

The old advice lasted partly because it sounded logical and was easy to follow. Fear played a part too, since a flare can be painful enough that people will cut out almost anything that might bring on another one, and giving up popcorn feels like doing something.

There is also a grain of truth that got stretched. During an active flare, doctors often do recommend a low-fibre diet for a short time to rest the bowel, and that temporary advice left many people believing those foods were dangerous for good. Some people ended up on a low-fibre diet for years, which runs against what the evidence supports. Niagara Health's patient guide now tells readers plainly that there is no need to avoid nuts, seeds, corn, and popcorn, and that the seeds in tomatoes, cucumbers, and strawberries are considered safe as well.

Which high-fibre foods actually lower your risk?

The habit with the strongest support is eating enough fibre, and high-fibre foods do that work. A low-fibre diet is a known risk factor for flares, and researchers think fibre helps by keeping stool soft and easing the pressure that straining puts on the colon wall. After age 50, the general targets are about 21 grams a day for women and 30 grams for men.

Most Canadians fall well short of that, with the Heart and Stroke Foundation putting the average intake at about 14 grams a day. A long-term diverticulitis diet is mostly an ordinary healthy one, built around oats, barley, beans, lentils, vegetables, fruit, and the very nuts and seeds people were once told to avoid. These steps make the change easier to stick with.

Add fibre slowly. A sudden jump can leave you gassy and uncomfortable, and if bloating keeps getting in the way, smaller daily increases usually help.

Drink more as you go. Fibre works best with fluid, and without enough water it can make constipation worse instead of better.

Build one high-fibre meal at a time. Swap white bread for whole grain at breakfast, or add a handful of lentils to a soup, before changing the whole day.

Keep moving most days. Niagara Health points to 30 to 60 minutes of moderate activity on most days of the week to help keep your bowels regular.

Respond to the urge to go. Delaying a bowel movement leads to harder stools that take more force to pass and raise the pressure inside your colon.

What should you eat when recovering from a flare?

When recovering from a flare, follow your own doctor's advice on what to eat in the short term. Many people start with a low-fibre or liquid diet while things settle, then bring fibre back gradually once they feel better, which is the approach that guidance from HealthLink BC describes as well.

The goal is to return to a higher-fibre diet, and staying on a restricted one forever works against you. If you are unsure how fast to add foods back, a registered dietitian can set out a plan that fits what you already like to eat. Our guide to the signs your digestive system is not working like it used to covers other changes worth watching.

When should you see a doctor the same day?

Book a regular appointment if you have belly pain that lasts more than a day or two, especially low on the left side, or pain that keeps coming back. You should see a doctor the same day if that pain comes with a fever, nausea, or a change in your bowel habits, because an untreated flare can get worse.

Go to the emergency department or call 911 if you have severe belly pain, a high fever, vomiting that stops you from keeping fluids down, blood in your stool, or a belly that is hard and very painful to touch. Doctors manage many mild flares at home, while more serious ones need hospital care. People who have repeated or complicated flares sometimes need surgery.

Frequently asked questions

Can you eat popcorn if you have pouches in your colon?

Most people with pouches in the colon can eat popcorn. A large study of about 47,000 men found that those who ate popcorn at least twice a week had a lower risk of a flare than those who rarely ate it. During an active flare, follow your doctor's short-term advice, which may mean avoiding popcorn until you recover.

Can seeds get stuck in colon pouches?

No study has ever proven that seeds lodge in colon pouches and cause infection, and studies in both men and women found no link between seeds and flares. Canadian hospital guidance now says the seeds in tomatoes, cucumbers, strawberries, and raspberries are considered safe. Seeds also add fibre, which helps protect the colon over time.

How much fibre do adults over 50 need each day?

Canadian guidance generally advises adults over 50 to aim for about 21 grams of fibre a day for women and 30 grams for men. Most Canadians eat only about half the fibre they need. Raise your intake slowly over a few weeks, and drink more water as you go, to avoid gas and bloating.

What does a sensible eating plan look like after a flare?

After a flare settles, most people move from a short low-fibre or liquid phase back toward a higher-fibre diet. A long-term diverticulitis diet looks much like any healthy diet, with whole grains, beans, lentils, vegetables, fruit, nuts, and seeds. A registered dietitian can help you pace the change so your gut adjusts comfortably.

Is lower left belly pain an emergency?

Lower left belly pain is an emergency when it is severe, when your belly is hard and very painful to touch, or when it comes with a high fever, vomiting, or blood in your stool. In those cases, go to the emergency department or call 911. Milder pain that lasts more than a day or two still needs a doctor's visit.

Can a flare clear up without a hospital stay?

Doctors manage many mild flares at home, often with rest and a short period of low-fibre or liquid eating. More serious flares, such as those with an abscess or a tear in the bowel, need hospital treatment. People who have repeated or complicated flares sometimes need surgery, so follow-up with your doctor matters.

Your next step

Whether you need that belly pain checked or want help building a fibre-rich diet you can live with, a walk-in doctor or a registered dietitian is the right place to start. The Medimap Health Hub has more on digestive health; you can book a visit at a walk-in clinic near you, and you can find a registered dietitian on Medimap.

Disclaimer: This article is for general information only and is not medical advice. It does not replace a conversation with a doctor or other qualified health professional who knows your history. If you think you are having a medical emergency, call 911 or go to the nearest emergency department.