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It’s Time to Rethink the Low-Fiber Low-Residue Diet

Written by Dr. Michael Ruscio, DC on August 25, 2022

Written by Dr. Michael Ruscio, DC on August 25, 2022 — Reviewed by Heidi Turner

Paleo and Low FODMAP Diets are Better for Healing Your Gut

• Low-Fiber Low-Residue Diet Basics|
• Clinical Uses|
• Where The Low-Residue Diet Falls Short|
• Diet Options for Gut Symptoms|
• The Bottom Line|

In my experience, diet is unquestionably the most impactful intervention for improving your gut and overall health. That being said, there are certain diets with very little research that tend to be recommended for digestive symptoms that just don’t make much of an impact. The low-fiber/low-residue diet seems to fit into this category.

Like many popular diet trends, the low-fiber/low-residue diet has a couple of principles such as restricting dairy and fiber that can be quite helpful. But, the diet on the whole doesn’t necessarily translate into clinical benefit and appears to provide hardly any advantages for healing your gut.

A low-fiber/low-residue diet restricts fiber (from whole grains, beans, and vegetables) and other foods (like milk) that can stimulate your bowels. The hope is that by restricting these foods, the size and number of bowel movements will be reduced, which will decrease painful symptoms like diarrhea, bloating, gas, and abdominal pain.

Although this diet is still being recommended for a variety of gastrointestinal conditions, there’s not enough evidence to support its use outside of some very specific situations like bowel preparation (prior to a colonoscopy or certain surgeries), abdominal adhesions, and gastroparesis [1]. In addition, this diet does not seem to reduce inflammation or target the underlying cause of GI symptoms [2].

However, there are plenty of effective dietary options that can treat your gut and give you symptom relief. In this article, we’ll break down the low-fiber/low-residue diet, including what the research says about its use. We’ll also discuss why you’ll likely get more benefit from following a more research-backed diet option like the Paleo or low FODMAP diet.

Low-Fiber Low-Residue Diet Basics 

It’s important to note that there’s no clinical definition or official list of approved foods for either the low-fiber or low-residue diet, and they’re often referred to interchangeably [3]. However, there are a few differences between the two. Before discussing the basics of each type of diet, let’s review the definitions of residue and fiber.

Residue refers to indigestible food or substances (such as dietary fiber, bacteria, and gastric secretions) that remain in the GI tract and contribute to the bulk of your stool [1, 2, 3].

Fiber refers to nondigestible carbohydrates and lignins (components of plant cell walls). Fiber can be non-fermentable (insoluble) or fermentable (soluble) by the bacteria in your colon, and both types can increase the size and weight of your stool [3].

What is a Low-Fiber Diet?

The current Dietary Guidelines for Americans recommendation is 14 grams of fiber for every 1,000 calories consumed for healthy people [4]. While there’s no clear definition, a low-fiber diet is generally assumed to be one with less than 10 grams of total daily fiber — which is less than half the daily recommendation for the average person [1, 3].

A low-fiber diet restricts high-fiber foods like:

• Beans and legumes
• Whole grains
• Brown rice
• Quinoa
• Flaxseed
• Raw fruits and vegetables

The goal of the low-fiber diet is to reduce the size of your stool and the number of bowel movements you have. However, simply cutting out fiber doesn’t address the root cause of digestive symptoms related to an imbalanced gut microbiome and/or inflammation.

Refined grains and sugars, which are allowed on this type of diet, can fuel inflammation and feed problematic bacteria leading to and exacerbating a variety of GI symptoms [5, 6, 7, 8].

What is a Low-Residue Diet?

A low-residue diet is a type of low-fiber diet that also restricts milk products. Milk is a low-fiber food but can increase residue in the colon and bulk the stool [1, 2]. The low residue diet restricts dietary fiber to less than 10 to 15 grams per day as well as other foods that can stimulate your bowels.

Just like with the low-fiber diet, the goal is to reduce stool size and bowel movements frequency to hypothetically improve painful GI symptoms [2, 9].

The low-residue diet has been recommended for a variety of digestive disorders since the early 1900’s and may still be recommended for [2, 9]:

• Recovery from bowel surgery (ileostomy, colostomy, bowel resection)
• Colonoscopy (a screening to examine the health of the large intestine)
• Symptom reduction from abdominal pain, cramping, and/or diarrhea
• Active flare-ups of Crohn’s disease or diverticular disease (infection in pouches formed in the colon)

It’s important to note that one 2015 literature review concluded: “there is insufficient evidence to further justify the clinical use of a low residue diet [1].” And the Academy of Nutrition and Dietetics officially removed the low-residue diet from the Nutrition Care Manual because there’s no scientifically accepted definition of residue or low residue, and there’s a lack of research into the effects of the low-residue diet [1].

Having said that, there’s not a lot of research to discredit the low-residue diet either. And there are a couple of principles of this diet like dairy and fiber restriction, that can be helpful for improving GI symptoms.

What Foods are Included on a Low-Residue Diet?

There’s no specific food list for a low-residue diet likely because [3]:

• It’s hard to predict the exact amount of residue produced by different foods.
• All foods can lead to some degree of residue within the intestine.
• The gut microbiome and bowel function of each person are variable.

The above points highlight why defining the low-residue diet can be so problematic, but there are still generally accepted foods. Here’s a list of some foods that may be included on a low-residue diet [9, 10, 11]:

• Well-cooked lean meat (like seafood and poultry)
• White rice
• Hard boiled eggs
• Limited amounts of fruit juice, tea, and coffee
• Vegetable juices (without pulp)
• White pasta
• Refined carbohydrates (plain bagels, white English muffins, white bread, plain crackers, white toast)
• Refined cereals (farina, cream of wheat, grits, puffed rice, corn flakes)
• Dairy products (limited to two cups per day, if tolerated)
• Well-cooked vegetables
• Raw, canned, or cooked fruits without the skins (apricots, bananas, cantaloupe, honeydew, watermelon, nectarines, papaya, peaches, plums, applesauce, and avocado)
• Gelatin
• Plain cakes, cookies, and puddings

Some of the foods on this list, like sugar and processed grains, are technically low residue but they offer no health benefits. Even worse, they can cause gut microbiome imbalances and inflammation leading to GI symptoms. Not to mention, the amount of allowed dairy is considerably high for a “low-dairy” diet, which undermines the premise of this diet.

What Foods are Avoided on a Low-Residue Diet?

The following chart lists the foods that are often restricted on a low-residue diet but again, there’s no universally agreed upon list [10, 11, 12]:

Now that you have a general understanding of how the low-fiber/low-residue diet works, let’s look at some of the research.

Clinical Uses of the Low-Residue Diet

While there’s not enough research or clinical evidence to support the use of the low-residue diet for common gut symptoms or conditions like IBS and inflammatory bowel disease (IBD) [1], it can be useful in a few specific situations [3, 13, 14, 15, 16, 17]:

• Bowel preparation prior to a colonoscopy 
• In preparation for and following bowel or gynecological surgery
• Abdominal adhesions (a type of internal scar tissue)
• Gastroparesis (a disorder where food doesn’t move through the stomach to the small intestine properly)

Low-Residue Diet for Bowel Preparation

Typical preparation for colon screening or surgery involves the use of a clear liquid diet and laxatives to clean the colon. The low residue diet has been found to be as effective as or better than a liquid diet for improving bowel cleanliness prior to a colonoscopy or other bowel procedure [3]. Patients who are allowed to consume a low-residue diet instead of a clear liquid diet for colon prep tolerate it better and are more willing to repeat the process in the future [14].

In addition, a 2021 systematic review and meta-analysis found that patients following a low-residue diet for bowel prep had fewer symptoms like nausea, hunger, and vomiting when compared to those on a liquid diet [14].

Other Uses of the Low-Residue Diet

Outside of colonoscopy prep, the usefulness of the low-residue diet seems to be limited. Here’s a breakdown of the current research:

• One 2014 randomized controlled trial found the low-residue diet was associated with less nausea, faster return of bowel function, and significantly shorter length of hospital stay after colorectal surgery when compared to a clear liquid diet [13].
• One 2022 randomized controlled trial found that women who consumed a low-residue diet three days before gynecological surgery had better bowel prep prior to surgery, shorter time in surgery, and a quicker return to normal bowel function after surgery when compared to those who consumed a regular diet [15].
• A 2022 literature review found the low-residue diet to reduce symptoms of gastroparesis [16].

Where The Low-Residue Diet Falls Short

When it comes to general GI symptoms and disorders like IBS and IBD, the low-residue diet doesn’t have any meaningful research to support its use. It doesn’t decrease inflammation or address the underlying cause of digestive conditions, and prolonged use of this diet may lead to nutritional deficiencies and can worsen symptoms like constipation [2].

In addition, one randomized controlled trial found patients with active Crohn’s disease (a form of IBD) who were following a low-residue diet had no difference in their symptoms after they reintroduced fiber [18]. However, the role fiber plays in IBD is unclear, as some people with Crohn’s disease may have difficulty digesting certain types of fiber. When in doubt, listen to your body. 

Lastly, the low-residue diet includes foods that can trigger inflammation and cause metabolic changes like sugar and processed foods. It also allows a fairly high amount of dairy (2 cups), despite being a low-dairy diet, which is known to cause digestive symptoms in many people.

Fortunately, there are several dietary options that include some aspects of the low-residue diet (like dairy and fiber restriction), are supported by research, and can treat the underlying cause of painful GI symptoms.

Diet Options for Improving Digestive Symptoms

If you’re struggling with digestive symptoms, it’s important to think about the fuel you’re providing your gut. A brief gut reset followed by a healthy gut-healing diet can help to calm down your symptoms and allow your gut to heal more completely.

While the low-residue diet is probably not the best diet option, there are a couple of principles of the diet that are helpful:

• Dairy is a major food allergen but also contains lactose (a sugar that’s difficult for some people to digest). Restricting dairy (as is done on the Paleo and low FODMAP diets) can be a good way to calm inflammation and create a healthy environment for your gut bacteria. 
• Dietary fiber can be problematic for some people with constipation and IBS symptoms, and low-fiber diets have been found to be beneficial for those with IBD, diverticulitis, bowel obstructions, and infectious GI diseases [1]. Restricting fiber for a time (as is done with the Low FODMAP diet) can reduce the fuel for problematic bacteria and help to reduce inflammation.

  Let’s review some preferred dietary options:

Elemental Diet

A short gut reset (24 to 48 hours) with an elemental diet like Elemental Heal may be helpful to calm inflammation and reduce the burden on your gut. The elemental diet is a liquid meal replacement that’s very easily absorbed in the digestive tract and supplies all macronutrients and essential vitamins.

The formula (hypoallergenic, anti-bacterial, and anti-inflammatory) is sold as a powder that you simply mix, blend, or shake up with water and sip on throughout the day.

Elemental diets have been found to improve small intestinal bacterial overgrowth and GI symptoms in IBS patients [5] and to reduce symptoms, maintain remission, and prevent relapse in those with Crohn’s disease [19].

If you complete a short gut reset, consider implementing it alongside a healthy, gut-healing diet plan to help maintain your results in the long run. If you’re new to making diet-related changes, I recommend starting with the Paleo diet.

Paleo Diet

A Paleo diet can calm inflammation by reducing your exposure to foods that provoke an immune and inflammatory response [7, 8]. This diet removes:

• Grains
• Beans
• Legumes
• Lentils
• Processed foods
• Dairy products
• Artificial sweeteners
• Alcohol

On the Paleo diet, you’ll eat the following foods for a few weeks:

• Fresh vegetables
• Fresh fruits (in moderation)
• Grass-fed, lean meats
• Fresh fish and eggs
• Healthy fats, like olive oil, coconut oil, avocado oil and avocados
• ​Nuts and seeds

If your symptoms significantly improve on the Paleo meal plan then stick with it and begin to reintroduce the healthy foods you’ve eliminated one at a time. If you’re not entirely happy with your results though, you may want to move to the low FODMAP diet.

Low FODMAP Diet

The low FODMAP diet is more restrictive than Paleo and targets possible underlying gut imbalances that could be causing inflammation. This type of diet starves overgrown or pathogenic bacteria and has been shown to improve IBS, IBD, and other functional GI disorders [6, 16, 18, 20, 21]. One literature review found the low FODMAP diet to be a first-line therapy for IBS and reports it’s preferable to the low-residue diet [1].

Here’s an overview of the low FODMAP diet:

If you’ve gone through the Paleo and low FODMAP plans but feel there’s still room for improvement, you may want to check out the autoimmune protocol diet, which is the most restrictive option of the three.

Autoimmune Protocol Diet

The autoimmune protocol diet (AIP) is a stricter version of Paleo eating that eliminates a wider variety of foods linked with triggering inflammation in those with autoimmunity. Because it’s so restrictive, the AIP diet shouldn’t be considered an initial treatment option. But if you’ve worked your way through the other meal plans and still have symptoms, this diet is one option that has been shown to help reduce IBD symptoms [22].

Here’s a chart of foods to include and foods to avoid on this type of diet:

The Paleo, low FODMAP, and autoimmune protocol meal plans have some great research and clinical evidence to support their use in healing a variety of GI complaints. You’ll likely experience much symptom relief rather quickly. 

But if you feel your gut needs more support, you can come back to the elemental gut reset at any point while you’re changing up your diet. Starting with one to two days is great but Elemental Heal can also be used for longer periods of time as a hard-hitting treatment.

Additionally, you can consider starting probiotics or other gut-healing supplements if you are seeking more symptom relief.

Paleo and Low FODMAP Diets are More Effective

There’s no clear definition of a low-fiber/low-residue diet, and there’s really no research to support its use outside of some very specific instances like colonoscopy prep. 

However, there are a couple of principles of the low-fiber/low-residue diet, like dairy and fiber restriction, that can be helpful. Healing your GI symptoms can best be accomplished by working your way through a short gut reset (with Elemental Heal) and moving toward a healthy, gut-healing meal plan like the Paleo or low FODMAP diet.

If you’ve tried diet therapy but still have uncomfortable symptoms, you may want to work through our step-by-step gut healing guide in Healthy Gut, Healthy You. For more personalized support, contact us at the Ruscio Institute for Functional Medicine.

The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.