Fiber is a substance in plant-based foods that remains undigested as it passes through the small intestine. A low-fiber diet contains foods that are easily digested and absorbed.
Following a low-fiber diet (also called a low residue diet) reduces the amount of undigested food moving through the small intestine, which reduces stool size and frequency. This is particularly important for people with inflammatory bowel disease (IBD) who are experiencing a flare-up.
People preparing for a colonoscopy may also need to follow a low-fiber diet, depending on their doctor’s recommendations.
With careful planning, it is still possible to get all the essential nutrients from a variety of low-fiber foods.
In this article, we look at what foods to include and those to avoid when following a low-fiber diet.
Most adults need fiber-rich foods to keep their digestive system healthy. However, a high-fiber diet is unsuitable for some people who have specific conditions so a low-fiber diet may be a better option.
Conditions that may require a person to eat a low-fiber diet include:
- a flare-up of IBD, including Crohn’s disease, ulcerative colitis, and diverticulitis
- an obstruction to part of the bowel
- before or after bowel surgery
A low-fiber diet can reduce the risk of the bowel becoming obstructed, or if the bowel is obstructed, it can reduce symptoms such as bloating or pain.
Foods to avoid on a low-fiber diet:
- Breakfast cereals, including muesli, bran flakes, puffed wheat, shredded wheat, porridge, granola, or cereals with added dried fruits.
- Whole-wheat bread, seeded loaves, and bread with added fruit, nuts, or seeds.
- All vegetable skins, peels, and seeds, including potato skins.
- Whole-wheat or brown pasta or grains, including brown or wild rice, bulgar wheat, quinoa, and couscous.
- Cakes or pastries with nuts, fruits, or seeds, including fig rolls, flapjacks, and fruit scones.
- Fruits with seeds and peels still attached, including raspberries, strawberries, blueberries, blackcurrants, passion fruit, kiwi, oranges, coconut, and fresh figs.
- All dried fruit, such as figs, prunes, dates, and raisins.
- Any raw, uncooked vegetables.
- Pulses, such as lentils, baked beans, kidney beans, and chickpeas.
- Seeds, such as pumpkin, sunflower, and flaxseeds.
- Nuts, including walnuts, brazil nuts, almonds, cashews, and crunchy peanut butter.
- Tough or fatty meat.
- Fish with bones and the skin still on.
- Caffeinated drinks, including coffee, black tea, and cola.
- Chunky soups.
Proper nutrition is crucial for the best management of IBD and other conditions that affect the bowel.
Some people only follow a low-fiber diet for short periods, while others may use it as a long-term strategy. Even if just following the diet for a for a short time, it is still important to try and eat a variety of foods.
The following foods may be included as part of a low-fiber diet, depending on individual symptoms and tolerance:
- low-fiber breakfast cereals, such as cornflakes and puffed rice
- gluten-containing products made from white flour, such as pita bread, naan bread, wraps, noodles, pasta, crumpets, and cream crackers
- gluten-free, starchy foods, such as white rice, rice cakes, and crackers
- cooked potatoes with skins removed
- small amounts of fruits with pits and skin removed, such as ripe banana, melons, and tinned fruit
- smooth fruit juice
- smooth peanut butter
- vegetables without peel, seeds, or stalks
- sieved soups or broths
- smooth tomato sauce
- dairy products in small amounts, only if they do not cause additional symptoms
- meat, fish, poached eggs, and tofu
Meal options for someone following the low-fiber diet include:
- low-fiber cereal (for example Rice Krispies, Cornflakes, Special K) with milk or non-dairy milk
- white bread or toast with butter and jelly
- poached eggs
- smooth yogurt or kefir
- applesauce with cinnamon
- a sandwich made from white bread with slices of turkey breast
- white pasta with tuna
- ripe banana
- plain biscuits
- canned mandarin oranges
- white rice with salmon and low-fiber vegetables
- chicken breast with mashed potato
When introducing new foods, add only one at a time. This will help a person identify foods that make their symptoms worse.
Read the labels on pre-prepared or packaged meals, as they may contain ingredients that trigger symptoms.
Avoid anything with bits in it, including yogurts, marmalade, mustard, popcorn, and crunchy peanut butter.
Here are some more useful tips for a low-fiber diet:
- sieve soups and lumpy stews
- eat small meals every 3–4 hours
- chew food slowly and thoroughly
- avoid large quantities of caffeine or alcohol
- avoid rich sauces and spicy foods
- consume only small amounts of dairy
- avoid fizzy drinks
- speak to a dietitian about what fruits and vegetables are safe to eat
If eating or digestion continues to be difficult or painful, it is essential to speak to a doctor. People with IBD may need considerable support from a dietitian to manage the disease during times of relapse and remission.
While much research is conflicting on the best dietary approach to prevent or delay IBD relapse, there is some evidence that supports a semi-vegetarian diet and exclusion diets.
It is vital to eat a varied diet that contains all of the essential nutrients and enough calories to maintain energy levels.