Ulcerative colitis is a chronic inflammatory bowel disease categorized by inflammation and lesions in the lining of your large intestine (or colon) and rectum. The development of the disease has been linked to a number of factors, including improper immune system response, family history, and the presence of other autoimmune conditions. While certain diet and lifestyle choices may contribute to the severity of ulcerative colitis symptoms, research is largely undecided as to the main cause of the disease. In addition to medical treatments, whole body interventions that incorporate therapeutic foods and stress management techniques may help improve your quality of life. (Source, Source, Source)

In this article, we’ll provide an overview of ulcerative colitis, how dietary choices may affect your symptoms, and what to eat during ulcerative colitis flare-ups, when symptoms can suddenly and intensely worsen.

General Symptoms of Ulcerative Colitis

Ulcerative colitis occurs when your immune system mistakenly destroys healthy tissues lining your large intestine, causing widespread inflammation and lesions. Symptoms of ulcerative colitis vary based on how much the disease has spread in your large intestine and to what extent associated inflammation levels are under control. Symptoms may subside for long periods of time, known as remission periods, or they may increase during active flare-ups of the disease. (Source, Source)

General symptoms of ulcerative colitis include:

• diarrhea
• passing blood with stool
• passing mucus or pus with stool
• feeling a constant need to defecate, even though your bowel is empty
• weight loss
• fatigue
• nausea
• vomiting
• fever
• joint pain
• skin rashes

(Source, Source)

Types of Ulcerative Colitis

Think of your large intestine (that consists of your cecum, colon, rectum and anus) as a muscular tube that’s bent in an upside-down U shape. The right and left bend can be used as landmarks to track how far your ulcerative colitis has spread. In knowing the areas of your large intestine affected by the disease, your health care provider can classify the type of ulcerative colitis you have and anticipate the symptoms you are most likely to experience. (Source)

1. Ulcerative Proctitis

Proctitis is inflammation of the rectum, and ulcerative proctitis is diagnosed when inflammation is limited to your rectum. You may have rectal pain and bleeding, and the need to have bowel movements may come on suddenly and urgently. (Source)

2. Proctosigmoiditis

Proctosigmoiditis is diagnosed when inflammation moves beyond your rectum and into the part of your colon that connects to your rectum, known as the sigmoid colon. If you have proctosigmoiditis, you may experience diarrhea and bloody stools, abdominal pain, or inability to pass stool despite the sensation of a full bowel. (Source)

3. Left-Sided Colitis

Left-sided colitis is diagnosed when inflammation is found within your rectum, and stretches up to the first bend of your colon. Symptoms of left-sided colitis may range from pain and weight loss to loose, bloody stools and urgency in passing stool. (Source)  

4. Pancolitis

Pancolitis, also known as extensive colitis, affects your entire large intestine. When inflammation is widespread and far-reaching, it can cause severe diarrhea and bloody stool, pain, cramping, loss of appetite and associated weight loss, and fatigue. (Source, Source)

Ulcerative Colitis & Your Microbiome

Your large intestine is home to trillions of microorganisms, known as your microbiome, that influences your overall health. The diversity of these predominantly bacterial populations found in your gut are unique to each person, based on a number of factors including:

• family history
• genetics
• lifestyle choices
• environmental exposures
• medication and antibiotic use
• diet

(Source)

Your microbiome plays a key role in the digestive process. When you eat a meal, food is broken down first in your mouth, then your stomach, and finally in your small intestine, where nutrients from your food are absorbed. The remaining contents then move into your large intestine, where microorganisms further digest materials from your recent meal. Waste is later expelled as a bowel movement. (Source)

The microorganisms of your large intestine break down materials from your food to synthesize vitamins and produce compounds that influence your metabolic health, your endocrine system, and your mood via communication pathways known as the gut–brain axis. Most importantly, these microorganisms influence your immune response. In fact, 70%–80% of your immune system is found in your large intestine. (Source, Source)

Target Dysbiosis Through Diet

Dysbiosis, or imbalances of gut microbiota associated with disease, can negatively influence your immune response. This can lead to your immune system mistakenly destroying healthy tissues, as is the case with ulcerative colitis. Targeting dysbiosis through diet to improve ulcerative colitis symptoms is becoming more accepted as we better understand the influence therapeutic foods can have on healthy microorganism diversity and inflammation levels in the body. (Source, Source, Source)

A number of dietary interventions may help reduce your symptoms of ulcerative colitis. For example, a personalized diet designed to target low grade, chronic inflammation by removing potential trigger foods and increasing anti-inflammatory foods has been studied for its positive effect on gut health. As nutrient deficiencies are common in people with ulcerative colitis, eating a variety of whole foods and working with a practitioner to optimize digestion may improve intake of vitamins and minerals, as well as increase microbial diversity in your gut. (Source, Source)

What to Eat During an Ulcerative Colitis Flare-Up

An ulcerative colitis flare-up follows a period of remission, which is characterized by minimal or nonexistent symptoms. During a flare-up, symptoms may suddenly and intensely worsen as a result of increased inflammation, sometimes without a clear cause.

Although dietary choices may not directly cause ulcerative colitis flare-ups, they can aggravate symptoms. Given increased irritation in your digestive tract, foods that may normally be safe for you during remission can be triggering during a flare-up. It’s important to work with your care team to design a personalized plan to reduce discomfort. (Source)

While a flare-up diet may vary between people, the Crohn’s and Colitis Foundation suggests trigger foods to avoid if you’re experiencing increased symptoms:

• high-fiber fruits with skin (such as apples)
• raw cruciferous vegetables (such as broccoli)
• whole nuts
• whole grains
• lactose (found in most dairy products)
• fruit juices
• sugary foods
• caffeine
• alcohol
• spicy foods
• fried foods

(Source)

Instead, a safer option may be focusing on lower fiber fruits (such as bananas or melon), cooked fruits, cooked vegetables without peels, nut butters (rather than whole nuts), and lean proteins (such as fish or poultry). It’s also important to drink plenty of liquids to avoid dehydration after fluid loss from diarrhea.  

In a 2020 study published in the journal Nutrients, 86% of people with inflammatory bowel disease reported that some foods were more likely to increase their symptoms, notably spicy foods, milk products, and sugary drinks. Study participants also reported that large meals appeared to cause more digestive issues than smaller, more frequent meals. A majority of participants also acknowledged that following a more controlled diet and limiting known trigger foods helped reduce their symptoms long term. (Source)

5 Medicinal Foods to Consider  

Certain therapeutic foods have been studied for their ability to reduce inflammation during ulcerative colitis flare-ups as well as to support longer periods of remission. While there is evidence to suggest these foods may provide support in tandem with medical treatment, studies are limited in number and in sample size. In some cases, further research with larger sample sizes is needed to increase confidence in the data.

1. Curcumin

Curcumin, derived from the turmeric root, is known for its anti-inflammatory properties and ability to block compounds that can cause inflammation and pain in your body. For that ability, curcumin is considered to be a natural pain-reliever. A 2022 meta-analysis review of 6 randomized controlled trials (the gold standard of research) published in the Journal of Ethnopharmacology found that curcumin, alongside medical treatment, may be effective for the prevention of relapse in people with ulcerative colitis. (Source)

2. Omega-3 Fatty Acids

Omega-3 fatty acids, including DHA and EPA, have been studied for their positive health benefits, including supporting immune response, cognitive function, and cardiovascular health. Omega-3 fatty acids are found in fatty fish (including salmon, cod, and sardines, among others), fish oil, and flaxseeds. Small studies show that when used in conjunction with medical treatment, omega-3 fatty acids target intestinal inflammation and may help to maintain remission. These studies vary based on the food source and dosage of omega-3 fatty acids, emphasizing the need for additional research. (Source, Source, Source)

3. Probiotics

Probiotics are living microorganisms found in supplements and certain foods that may influence immune response and add to the diversity of your gut microbiome. According to a 2020 meta-analysis review, there is some evidence to suggest that certain strains of probiotics may help to encourage ulcerative colitis remission, although no more so than conventional treatments.

A 2015 meta-analysis review of 6 clinical trials published in the Journal of Gastrointestinal and Liver Diseases found that a specific strain of probiotics known as Escherichia coli Nissle 1917 was as effective as gold standard medical treatment for keeping people with ulcerative colitis in remission. Although these results are promising, Escherichia coli Nissle 1917 is not approved as a dietary supplement in the United States because it is too closely related to E. coli strains that cause illness. (Source, Source, Source, Source)

4. Extra Virgin Olive Oil

Extra virgin olive oil (EVOO) contains compounds with anti-inflammatory properties. In one study, EVOO consumption reduced intestinal inflammation in mice with induced colitis. In another small study measuring inflammatory markers in patients with ulcerative colitis, EVOO consumption reduced symptoms, improved gastrointestinal function, and lowered inflammation levels. EVOO is a part of the Mediterranean-style diet and one of the diets recommended by the International Organization for the Study of Inflammatory Bowel Disease. A study of people with ulcerative colitis and Crohn’s disease found that a Mediterranean-style diet reduced inflammation and symptoms, and improved nutritional status over 6 months. (Source, Source, Source, Source, Source)

5. Wheatgrass Juice

Wheatgrass juice contains chlorophyll, a plant pigment with anti-inflammatory properties that gives this food its bright green color. In a 2002 randomized, double-blind, placebo-controlled study published in the Scandinavian Journal of Gastroenterology, patients with ulcerative colitis who drank wheatgrass juice experienced reduced symptoms, notably less rectal bleeding. A 2022 study published in the American Journal of Physiology found that the green plant pigment reduced intestinal inflammation in mice, making the case for increasing consumption of green vegetables due to their chlorophyll content. (Source, Source, Source)  

How a Personalized Diet Supports Digestive Health

Making changes to your diet in light of ulcerative colitis or another autoimmune condition is best accomplished with the support of a knowledgeable guide, trained in nutrition therapy. Numerous elimination diets that focus on removing specific food groups have been studied to see if they work alongside conventional medical treatment to maintain remission. According to the Crohn’s and Colitis Foundation, research on the anti-inflammatory diet, the autoimmune protocol diet, the specific carbohydrate diet, and the ulcerative colitis exclusion diet show promise. Given the complexities of each diet, working with a nutritional therapist or dietician from WellTheory can ensure your individual needs are met and the nuances of your health history are being taken into account. (Source)

The Bottom Line on What to Eat During an Ulcerative Colitis Flare-Up

While changing your eating patterns during an ulcerative colitis flare-up may help reduce painful symptoms, these temporary dietary restrictions can usually be relaxed during times of remission. Still, to reduce the likelihood of a flare-up, eating a diet focused on whole foods in alignment with your own unique needs may help reduce the effect long-term inflammation can have on your overall gastrointestinal health. Incorporating therapeutic foods may further support your digestive function, microbiome diversity, and positively influence your quality of life. For personalized guidance in implementing therapeutic foods into your lifestyle, work with WellTheory’s Care Team.