IBS and GERD: How Acid Reflux and IBS are linked

Understanding IBS

IBS affects 1 in 7 people worldwide. (1) It is a ‘functional’ disorder as there are no observable signs of damage to the intestines, despite symptoms. IBS is a collection of GI symptoms that commonly occur together and include:

• Abdominal pain
• Diarrhea or constipation
• Bloating and gas
• Cramping
• Changes in stool consistency (2) 

What causes IBS?

We do not know what causes IBS, although the gut-brain connection is thought to be important. The biopsychosocial model proposes that mental and physiological factors are linked. This model explains how significant loss, trauma, or family influences may lead to the onset of IBS. (3, 4, 5)

Known risk factors for developing IBS include:

• Existing mental health conditions (e.g., depression and anxiety)
• Family history of IBS
• Severe stomach infection
• Changes to the immune system and nervous system
• Social factors such as lack of perceived social support
• Being female (6, 7, 8, 9) 

Understanding GERD

GERD is a common illness that affects approximately 20% of people worldwide. (10) In GERD, the muscles at the bottom of the esophagus do not work correctly, causing acid reflux. Symptoms of GERD include:

• Heartburn (indigestion)
• Regurgitation of stomach contents (acid reflux)
• Sore throat
• Chronic cough
• Difficulty swallowing (dysphagia)
• Nausea
• Vomiting
• Chest pain (11)

What causes GERD?

A ring of muscles known as the lower oesophageal sphincter is typically contracted to prevent reflux. When you swallow food, these muscles relax to allow food to pass into the stomach. GERD occurs when these muscles relax at inappropriate times, allowing stomach contents to move back up the esophagus, causing ‘heartburn.’ (12)

Several risk factors weaken the pressure by the oesophageal sphincter and contribute to GERD, including:

• Obesity
• Pregnancy
• Smoking
• Eating large meals, or eating late at night
• Eating trigger foods such as fried food
• Drinking alcohol or caffeine (13, 14)

In some cases, GERD may result from another issue, such as hiatal hernia or tumor. (15, 16)

What is the connection between GERD and IBS?

As many as 2 out of 3 people with IBS also have symptoms of GERD. (17) GERD and IBS both impact segments of the digestive tract, but the connection between the two is unclear. Theories explaining the overlap include:

• ‍Pain sensitivity: Both conditions arise when nerves in the gut become over-sensitive (visceral hypersensitivity). This causes changes in the muscle contractions of the intestines and esophagus.
• ‍Confusion over symptoms: IBS patients with GERD symptoms may actually have functional dyspepsia (indigestion). This is a milder form of GERD. Tests such as ambulatory oesophageal pH monitoring can confirm a diagnosis of GERD.‍
• The broad definition of GERD: GERD symptoms vary in severity. IBS-like symptoms may be part of the same spectrum of GERD, leading to patients reporting symptoms of both conditions. (18, 19, 20)

Complications

IBS is not usually associated with any long-term complications. By contrast in GERD, the backwash of acid may irritate the lining of your esophagus and cause inflammation. This may lead to:

• ‍Narrowing of the esophagus. The lower part of the esophagus may be damaged by stomach acid, causing a build-up of scar tissue. The scar tissue may narrow the food pathway and cause problems swallowing.‍
• Oesophageal ulcers: The lining of the esophagus to be worn away, causing open sores (ulcers) to form. This may cause pain during swallowing.‍
• Precancerous changes: Damage from stomach acid may lead to the lining of the esophagus becoming thick and red. This change increases the risk of oesophageal cancer and is known as Barrett’s esophagus. (21, 22) 

Diagnosing IBS

IBS is usually diagnosed based on pain in the abdomen for at least 12 weeks in a year associated with at least two of the following:

• Changes in stool frequency
• Changes in stool appearance
• Pain changes during a bowel movement (23)

However, IBS symptoms overlap with other conditions such as lactose intolerance. Therefore, your doctor may recommend the following additional tests to rule out other conditions: 

• ‍Hydrogen breath test: to identify bacterial overgrowth in the small intestine. This can also be used to detect lactose intolerance.‍
• Upper endoscopy: a long, thin, flexible tube with a camera attached is inserted down the throat to the small intestine. The camera is used to inspect for signs of bacterial overgrowth. A biopsy can be taken to test for coeliac disease.‍
• Stool sample: a stool sample is examined for parasite or bacterial infection. Your doctor may also check for signs of blood in the stool.‍
• Colonoscopy: checks for conditions such as colon cancer or symptoms of inflammatory bowel disease (IBD).‍
• Abdominal ultrasound: assesses the organs of the abdomen for signs of disease.‍
• Blood test: to examine markers in the blood for problems such as coeliac disease. (23, 24)

Diagnosing GERD

GERD may be diagnosed from a history of symptoms – particularly how frequently you experience acid reflux. The following tests may confirm the diagnosis:‍

• ‍Upper endoscopy: a thin, flexible tube with a camera is inserted into the mouth and down the throat to examine the esophagus. Visible inflammation of the esophagus caused by acid reflux indicates GERD.‍
• Ambulatory acid pH test: a small monitor is placed in your esophagus to measure if and when stomach acid is regurgitated. The monitor is often a clip inserted during endoscopy or is a catheter inserted through the nose and down the esophagus.‍
• X-ray of the digestive tract: first, you will drink a chalky solution called barium. This coats the inside of the esophagus and intestines and makes it easier to visualize any problems using an x-ray scan to observe signs of GERD.‍
• Manometry: a long tube is inserted into the esophagus. This measures the force of the esophagus muscles and rhythmic contractions of your esophagus when you swallow. (25, 26)

Treatment for IBS

Lifestyle factors are generally recommended for improving symptoms of IBS. But medications treating specific symptoms are also available.

Low FODMAP diet

This diet removes certain short-chain carbohydrates from the diet. These are poorly digested by the gut known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). This prevents bacteria in the gut from consuming FODMAPS and releasing gas to cause symptoms. (27)

High FODMAP foods to avoid:

• ‍Wheat products such as breakfast cereals, pasta, biscuits, and bread‍
• Dairy products such as cream cheese, milk, ricotta and yogurt‍
• Vegetables such as onion, garlic, and mushrooms‍
• Fruits such as apples, mangoes, apricots and peaches‍
• Legumes such as black beans and kidney beans‍
• Sweeteners such as fructose, honey, and polyols found in chewing gum (27) 

The low FODMAP diet improves symptoms in over 70 percent of people with IBS. (28) 

Psychological therapies

Stress management strategies work on the mind-body connection and have been shown to reducing IBS symptoms. These include:

• ‍Hypnotherapy. Hypnotic induction and suggestions shift how the brain responds to gut signals. This technique relieves symptoms in over 70 percent of people with IBS. (28)‍
• Mindfulness Meditation. This involves sustained present-moment attention and has been shown to reduce abdominal pain, bloating, and other IBS symptoms. (29)‍
• Yoga. Has been shown to relieve specific symptoms of IBS, such as diarrhea. A study in adolescents showed yoga lowered scores for gastrointestinal symptoms. (30)

Medication

A wide variety of pharmaceuticals treat symptoms of IBS. These may be over-the-counter medications or prescription and include:

• ‍Fiber supplements: such as Metamucil to decrease constipation in constipation-dominant IBS.‍
• Laxatives: to improve the movement of contents through the intestines and decrease constipation.‍
• Antidiarrhea medications: such as loperamide reduce diarrhea as a symptom of IBS.‍
• Antispasmodics: to reduce spasming of the colon, associated with abdominal pain.‍
• Antidepressant medications: such as tricyclics antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) to relieve abdominal pain. These medications are usually prescribed in small doses for IBS.‍
• Pain medication: such as opiates like codeine, may relieve abdominal pain and improve symptoms of diarrhea. (31, 32)

Treatment for GERD

Lifestyle factors are generally recommended as the first line of treatment for GERD. Medication and, in rare cases, surgery may also be prescribed. 

Lifestyle changes

The following changes may improve symptoms: 

• Losing weight, if you are overweight or obese
• Avoiding trigger foods
• Raising the head of the bed
• Quitting smoking
• Eating smaller meals
• Not eating before bed (33, 34)

Psychological therapies

Hypnotherapy. Hypnosis has also been shown to improve reflux symptoms by reducing anxiety, body vigilance and visceral sensitivity.

Medication

Lifestyle and dietary changes can benefit many people with IBS and GERD. However, if GERD symptoms persist, your doctor may recommend the following:

• ‍Proton pump inhibitors: lower the amount of acid produced in the stomach. Common PPI’s include esomeprazole, lansoprazole and omeprazole.‍
• Antacids: to relieve heartburn and other mild symptoms of GERD. Over-the-counter medications include Maalox, Mylanta and Riopan.‍
• H2 blockers: to decrease acid production to relieve symptoms of GERD. Over-the-counter H2 blockers include cimetidine, famotidine and nizatidine. (35, 36)

Surgery

In rare and severe cases, you may require surgery for GERD. The most common procedures are:

• ‍Fundoplication: a surgeon performs this using a laparoscope – a thin tube with a video camera. In this ‘keyhole surgery’ the top of the stomach is sewn to the esophagus, creating a one-way valve meant to prevent acid reflux.‍
• Endoscopic techniques: Endoscopic sewing is used to physically constrict the muscles of the sphincter. This adds pressure to the esophagus and minimizes acid reflux. (37)

The Wrap Up

IBS and GERD commonly overlap. The co-occurrence of the two gastrointestinal conditions may be due to changes in the nervous system that alter digestion. Otherwise, it may be due to the broad spectrum of GERD symptoms or overlapping symptom classifications. Fortunately, lifestyle changes and medication treatment may improve symptoms of both conditions.