Functional Abdominal Pain Symptoms

  • Are recurring/chronic
  • Can be debilitating and intense
  • Can be sharp, dull or achy
  • Can feel like cramps or bloating
  • Can appear suddenly, come and go, develop over time or last for months.
  • Usually occurs near the belly button, but can be anywhere in the abdomen
  • Can significantly impact your quality of life
  • Some studies show an association between psychological disorders and functional pain disorders such as anxiety and depression
  • Can occur day or night
  • May or may not be connected to eating or pooping
  • Each episode can last minutes to hours
  • Can result in missing school, daily activities and social interaction
  • Can be triggered or worsened by certain situations like traumatic life events or significant stress
  • Some patients have other symptoms with their functional abdominal pain such as nausea, vomiting, gas, bloating, diarrhea, constipation, heartburn; others have no other symptoms besides pain

In functional abdominal pain, there are bad signals between the brain and gut.  To understand better, it helps to highlight the brain-gut connection (sometimes called the brain-gut axis). Yes, there is a brain-gut connection.  All of us have a head brain and a gut brain.  With functional abdominal pain, there can be changes in the brain-gut connection and the ability of the nervous system to regulate the pain signals from the gastrointestinal (GI) tract.

Most of the time, the enteric nervous system controls the speed at which food moves through your GI tract, the fluids that need to be released for proper digestion and gathers nutrients from food all while you are going about your day unaware.  The ENS is the director of digestion, calling all the shots.  The ENS is constantly sending signals to your brain which may or may not come to your conscious awareness.  You can think of it as a never-ending group chat between the nerves in your gut and parts of your brain. The interactions are complex and finely tuned messages need to flow both ways.  There is a massive connection between your gut brain and head brain.  The biggest communication pipeline between the gut and the brain is the vagus nerve.

 

 

Your Gut Brain

Your gut brain has between 50-100 million neurons that have many ways of connecting with your head brain.  Gut neurons start in the esophagus and end at the rectum.  The gut is the only organ that has its own nervous system- the enteric nervous system (ENS).  The enteric nervous system can do its work without the brain’s help.  In fact, most people digest their food and are happily unaware of the complex work of digestion.  It is only when you have heartburn after eating a greasy pizza or after you had a bout of food poisoning where you become very aware that something is wrong with your current digestion.  For people with functional abdominal pain, they are very aware of what’s going on in their gut.  They experience something called visceral hypersensitivity where their gut neurons become highly sensitive.  In those cases, teens with functional abdominal pain are more sensitive to the normal process of digestion.  The sensations of normal digestion such as food moving through the GI tract and normal contractions can feel painful.  Basically, teens with functional abdominal pain have a lowered pain threshold in their abdomen and feel pressure, bloating and digestion more intensely than other people.

 

The Vagus Nerve and Amygdala

As the fastest and most important route from the gut to the brain, the vagus nerve is the biggest link between the gut and the brain. The vagus nerve carries information between the stomach and intestines and your brain, telling the brain how the gut is doing.  If the nerves in the gut are hypersensitive, the messages being sent to the brain through the vagus nerve can tell the brain, “you are in pain.”  There can be mixed up signals and the brain can interpret normal digestion as painful. The vagus nerve can deliver messages that are scrambled, mixed-up or misunderstood.  It’s like a car alarm. Some go off easily, others only trigger if you shake hard. If you have a disorder of the gut-brain interaction, it doesn’t take much for your alarm to go off. When that happens, you experience pain.

Several areas of the brain receive the messages from the gut and are involved in the sensation of abdominal pain.  One area of the brain that is very important in processing sensory information from the gut is the amygdala which controls fear, anxiety, and pain.  The amygdala is a small, almond-shaped structure located within the temporal lobe of the brain.  The amygdala is like a library, storing memories of emotions and sensations that you have experienced over your lifetime. If a teen has experienced abdominal pain in the past, the amygdala stores that memory and can run a repetitive loop of pain, even when the gut is not really not in pain.  In some patients with IBS, the amygdala can be hyperactive and can contribute to worsening pain or fear of symptoms.

Perception of Pain

This is how the perception of pain can be affected by life experiences or emotions.  The emotion or life experience is not causing the pain but it may be involved in the interpretation of normal signals as painful.  Stressful life events such as parent divorce, bullying, death of a loved one, or school pressures can make functional abdominal pain worse.  Many common phrases highlight the connection between the brain and the gut.  A teen with IBS can have corrupted signals from the gut to the brain that don’t match what’s actually happening in the gut.  When a teenager has functional abdominal pain, essentially the gut and the brain are not communicating like they should be.

GUT PHRASES

  • “Butterflies in your stomach” when you are nervous or excited
  • Gut is “tied up in knots” when you are anxious
  • “Punch in the gut” when you get unexpected news
  • “Go with your gut” when facing a big decision