Foods For Constipation: A Complete Guide (2024)

Chronic constipation (CC) is one of the most common gastroenterological diagnoses in clinical practice. Treatment includes several steps, depending on the severity of symptoms. Lifestyle modifications and increased intake of fiber and water are suggested by most health professionals. Unfortunately, the recommendations in this regard are the most varied, often conflicting with each other and not always based on solid scientific arguments. This blog aims to clarify this topic by providing practical indications for the management of these patients in every day clinical practice by using foods for constipation.

Diagnosing Constipation

The American Gastroenterological Association criteria utilise colonic transit and anorectal tests to classify constipated patients into one of the three groups (source):

1. Normal transit constipation.
2. Slow transit constipation.
3. Pelvic floor dysfunction or defecatory disorders.

Functional constipation and constipation-predominant IBS (IBS-C) are defined only by symptoms (source). Functional constipation must include 2 or more of the following:

• Straining during more than 25% of defecations
• Lumpy or hard stools more than 25% of defecations
• Sensation of incomplete evacuation more than 25% of defecations
• Sensation of anorectal obstruction/blockage more than 25% of defecations
• Manual manoeuvres to facilitate more than 25% of defecations
• Fewer than 3 spontaneous bowel movements per week

The two other criteria are:

• Loose stools are rarely present without the use of laxatives.
• The patients has insufficient criteria for a diagnosis of irritable bowel syndrome.

What Causes Constipation?

Intestinal Methanogen Overgrowth.

Foods For Constipation

Mineral Water

“Magnesium sulfate-rich mineral waters have been used for centuries for their laxative properties” (source)

It’s interesting that the first line of treatment for chronic constipation is enauring an adequate intake of water, even though this recommendation is not based on strong evidence. Having said that, the laxative action of waters, especially those rich in magnesium and sulfates, has been known for a long time.

Waters rich in magnesium sulfate may be helpful in constipation do to the magnesium compounds they contain. Magnesium oxide has been used for a long time in constipation, sometimes at doses higher than 2 g/day.

The main effect of magnesium is the osmotic effect due to its incomplete absorption. However, other mechanisms are being hypothesised, such as an increased secretion of cholecystokinin (CCK) and Peptide YY (PYY), which are known to modulate gut motility, and nitric oxide synthase (NOS), which acts on smooth muscle.

Moreover, a further mechanism of action could be due to sulfates, which can have a prebiotic action.

Mineral water therefore is the first of our list of foods for constipation.

Dietary Fiber

Fiber often gets luped together as if it is one thing, but there are different types with quite different solubility, fermentability, and viscosity, meaning they have different effects on the gut:

• Solubility, which depends on their hydrophilicity (physical property of molecules to bind with water).
• Viscosity (degree of resistance to flow).
• Fermentability – their capacity to be fermented by our gut bacteria..

Fiber can therefore be further divided into:

• Soluble, viscous, fermentable (e.g., guar gum)
• Soluble, viscous, unfermentable (e.g. psyllium)
• Soluble, non-viscous, fermentable (e.g. inulin, FOS, GOS, pectin)
• Soluble, non-viscous, unfermentable (e.g. PHGG—a great prebiotic I blog about a lot)
• Insoluble and slowly fermentable (e.g. wheat bran, resistant starch)
• Insoluble and unfermentable (e.g. cellulose, lignin)

Rapidly fermented soluble fiber is found in legumes, wheat, potatoes, rice, barley and rye. It acts as a prebiotic, thereby increasing fecal mass.

Soluble fiber that is only moderately fermented acts by retaining large quantities of water, forming gels, normalising fecal consistency, and it is the most widely studied fiber as regards its action on functional constipation and IBS-C.

Insoluble types of fiber, such as wheat bran, act on intestinal transit by means of an irritative stimulus on the mucosa, which, in turn, induces secretion of water and mucus. However, this is achieved only by the larger and coarse bran particles, while the finer and smooth ones have not been shown to share this laxative property.

Is There Real Evidence For Fibre?

A systematic review by Suares et al. analysed six randomised control trials in chronic constipation patients, four of which used soluble fiber and two used insoluble fibers. Compared to the baseline, soluble fiber led to an improvement in global symptoms, straining, pain on defecation, and stool consistency. It also increased the mean number of bowel movements per week and decreased the number of days between them.

Conversely, data regarding insoluble fiber were conflicting.

Another meta-analysis by Yang et al. showed that dietary fiber had a significant advantage over the placebo only in terms of stool frequency. There was no significant difference in stool consistency, laxative use, and painful defecation between the two groups.

A systematic review by Rao et al. recently analysed 11 studies. Due to the study heterogeneity and methodological quality, it was not possible to perform a meta-analysis. However, fiber was beneficial in five out of seven studies involving CC patients and in three out of three involving IBS-C patients. The authors conclude that fiber supplementation is beneficial in mild to moderate CC and IBS-C patients.

So the jury is till out it seems! Which is exactly my experience supporting clients with chronic constipation – some respond and some don’t. It will depend on the actual mechanism causing the constipation in each indivifual.

So despite the fact that fiber for constipation has relatively little support in the research, it is often suggested as a first-line treatment!

Plums

Plums are on the list of good foods for constipation. A randomised clinical trial compared the effects of dried plums and psyllium in patients with CC. Forty subjects were enrolled in an 8 week, single-blind, randomised cross-over study. Subjects received either dried plums (50 g twice per day) or psyllium (11 g twice per day) for 3 weeks each, with a 1 week washout period. This equated to the same amount of fibre, 6g.

The number of complete spontaneous bowel movements per week and stool consistency scores improved significantly with dried plums when compared to psyllium.

Kiwi

Kiwi fruits are well known for their laxative properties, and thus on the list of great foods for constipation. They are high in vitamin C and contain a wide range of other nutrients, such as fiber, potassium, vitamin E and folate, and various bioactive components. The latter include an array of antioxidants, phytonutrients, and enzymes, all able to provide functional and metabolic benefits.

In a study carried out by Rush et al., 42 subjects aged >60 years were recruited. During the 6 week study participants were randomly assigned to one of two trial groups. One group consumed kiwi fruit only in the first 3 week period, while the other group consumed kiwis only for the second 3 week period. Kiwi fruit consumption was set at one kiwi (100 g) per 30 kg of body weight per day. Kiwi consumption was associated with a significant increase in frequency of defecation, stool volume and softness, and ease of defecation.

The authors conclude that kiwi fruits are effective food for constipation. As well as dietary fibre in kiwis being helpful, the authors hypothesised the potential role of actinidin. Actinidin is a cysteine protease that enhances protein digestion and decreases gut transit time.

Pineapple & Papaya

Other protease cysteines, apart from actinidine, which are potentially effective on constipation, are found in pineapple and papaya.

Prunes

In one study evaluating kiwi, psyllium, and prunes in 79 patients with constipation it was those randomsied to kiwi that reported significant improvement in bloating scores. Eligible patients had <three complete spontaneous bowel movements (CSBMs) per week and were partially randomised to green kiwifruit (2/d), prunes (100 g/d), or psyllium (12 g/d) for 4 weeks.

There was a significant improvement in all three treatments; stool consistency significantly improved with kiwifruit and prunes; straining significantly improved with kiwifruit, prunes, and psyllium.

Fig Paste

Another consideration when thinking about foods for constipation is fig paste, in a study carried out on a constipation rat model, was able to improve constipation, increasing fecal output and water content, and decreasing transit time. The results were confirmed by a randomised, double-blind, placebo-controlled study investigating 80 constipated patients.

Fig paste administered for 8 weeks showed a greater improvement in colon transit time, stool consistency, and abdominal discomfort compared with the placebo.

Flaxseed

In particular, flaxseed could be one of many great foods for constipation because it is a good source of soluble and insoluble fiber. 50 g of flaxseed contains 13.3 g of dietary fiber, about 50% of the recommended daily intake.

Moreover, due to its lipid content and mucilaginous component, flaxseed also has lubricating and stool-softening properties. In a recent randomised controlled trial, 90 patients with FC were enrolled: 60 patients assumed flaxseed flour-enriched meals (50 g/day) and 30 patients lactulose (15 mL/day) for 4 weeks. Patients treated with flaxseed flour reported an improvement in bowel movement frequency and abdominal pain severity and less difficult defecation than those taking lactulose.

Fermented Milk

Some studies suggest that probiotics and fermented milk can improve defecation in constipated patients. However, the mechanism of fermented milk containing probiotics on constipation remains poorly understood. Researchers recently studied 26 volunteers with chronic constipation symptoms treated with 200 g/d of fermented milk containing Lactobacillus casei Zhang and Bifidobacterium animalis ssp. lactis V9 for 4 weeks.

After the intervention a significant improvement of constipation symptoms was observed.

The authors speculate that it was due to three potential mechanisms: an improvement of gastrointestinal microbiota, a decrease in inflammation, and a positive action on the regulating metabolic pathways. (source)

High Fiber Food Chart For Constipation

Almonds – 28 g	3.3	13
Apple – 1 medium	3.3	13
Artichoke – 1 piece	6.5	26
Banana – 1 medium	3.1	12
Black beans – ½ cup	7.5	30
Bran ready-to-eat cereal – ½ cup	8.8	35
Broccoli – ½ cup	2.8	11
Chickpeas – ½ cup	6.2	24
Figs, dried – ¼ cup	3.7	14.5
Green peas – ½ cup	4.4	18
Lentils – ½ cup	7.8	31
Navy beans – ½ cup	9.5	38
Oat bran – ¼ cup	3.6	14
Orange – 1 medium	3.1	12
Peas – ½ cup	2.5	10

Foods For Constipation

Kiwis, pears, apples, apricots, dried plums, and figs are the most frequently recommended fruits for CC management. They can be eaten both during and outside of meals. Bran and powdered fiber supplements may be helpful when a sufficient amount of fiber is not taken through food. They can be added to cereals, yogurt, fruit juices, or soups. The enrichment of the diet with fiber should be slow and gradual in order to avoid (or reduce) disturbances such as bloating, flatulence, and intestinal cramps.

The consumption of at least eight glasses (1.5–2 L) of fluids daily is recommended to facilitate the laxative effectiveness of fiber intake.