Unexplained symptoms are worth exploring, but it's important to first speak to your GP and have potential medical causes appropriately investigated. This library is for information only and does not replace medical advice, diagnosis or testing.
-
Gastrointestinal distress is a broad term describing uncomfortable or disruptive symptoms affecting the digestive system, including the stomach and intestines.
These symptoms can include abdominal pain, bloating, nausea, cramping, changes in bowel movements, feelings of fullness and digestive discomfort.
For some people, digestive symptoms are occasional or relatively mild. For others, they can be persistent, unpredictable and significantly affect everyday life.
Digestive symptoms are associated with a wide range of conditions, including Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), gastroparesis, food intolerances, functional digestive disorders and other chronic illnesses.
Although these conditions can share symptoms, they are distinct. IBS involves changes in gut-brain interaction, IBD involves inflammation of the digestive tract, and gastroparesis affects the movement of food through the stomach.
Digestive symptoms can also occur alongside conditions such as ME/CFS, Long COVID, fibromyalgia and dysautonomia.
-
The heart has its own electrical system, which controls the timing and rhythm of each heartbeat.
Heart rate is also influenced by the autonomic nervous system, which regulates automatic bodily functions such as breathing, digestion, blood pressure and circulation.
The sympathetic nervous system: Helps prepare the body for action by increasing heart rate and supporting the circulation of blood to muscles and other tissues.
The parasympathetic nervous system: Helps regulate heart rate during quieter states, including rest and recovery.
These systems continuously adjust cardiovascular activity in response to the body's changing needs.
-
Digestion involves a complex interaction between the digestive organs, nervous system, immune system and brain.
The gastrointestinal tract contains an extensive network of nerves known as the enteric nervous system, sometimes called the second brain.
This network helps regulate the movement of food, digestive secretions and communication between different parts of the gut.
The Gut-Brain Connection
The gut and brain communicate continuously through what is known as the gut-brain axis.
This communication involves the nervous system, hormones, immune signalling and the gut microbiome.
Signals travel in both directions. The digestive system can influence how the brain processes sensations, while the brain can influence digestive movement, sensitivity and function.
This helps explain why digestive symptoms can be closely connected to emotional states, stress and nervous system activity.
For example, someone might experience abdominal discomfort or an urgent need to use the toilet before an important event, even without consciously feeling anxious.
The Stress Response and Survival Mode
When the body enters a state of heightened alertness, commonly described as fight-or-flight or survival mode, the autonomic nervous system can alter digestive activity.
During an acute stress response, the body prioritises functions associated with responding to a perceived threat.
This can influence:
The speed at which food moves through the digestive system
Stomach and intestinal contractions
Digestive secretions
Sensitivity to sensations within the gut
Bowel urgency and abdominal discomfort
For some people, prolonged periods of stress are associated with persistent digestive symptoms.
The body's stress response can also occur without someone consciously recognising anxiety or emotional distress.
Visceral Hypersensitivity
Visceral hypersensitivity describes increased sensitivity to sensations originating from internal organs, particularly the digestive tract.
In some digestive conditions, the nervous system may respond more strongly to sensations such as stretching, pressure or normal intestinal movement.
As a result, ordinary digestive processes can feel uncomfortable or painful.
This is particularly relevant to disorders of gut-brain interaction, including IBS.
The sensations are real physical experiences, even when routine investigations do not identify structural abnormalities.
Emotional Experiences and Digestive Symptoms
Emotions and digestion are closely connected.
Fear, excitement, sadness, anger and anticipation can all influence gastrointestinal activity through changes in autonomic nervous system function.
Some mind-body approaches also explore the relationship between emotional suppression, longstanding stress and physical symptoms.
For example, someone who has spent extended periods managing difficult emotions or remaining highly alert to their surroundings may experience changes in muscle tension, breathing and digestive activity.
Emotional suppression has been associated with physiological stress responses in some research, although it is not an established direct cause of conditions such as IBS, IBD or gastroparesis.
Digestive symptoms can involve several interacting processes, and the contribution of stress and emotions varies between individuals.
-
The gut and brain are closely connected.
The digestive system and nervous system communicate continuously. Changes in stress, emotions and physiological arousal can influence digestive sensations and activity.
Digestive symptoms are not always related to food.
Although eating and digestion can influence symptoms, gastrointestinal discomfort can also occur independently of meals.
IBS and IBD are different conditions.
IBS is a disorder of gut-brain interaction affecting bowel function and sensation. IBD, including Crohn's disease and ulcerative colitis, involves inflammation of the digestive tract.
Digestive symptoms can occur without visible abnormalities.
Some people experience significant pain, bloating or altered bowel habits despite routine investigations appearing normal. This does not make their symptoms any less real.
Stress can affect digestion without conscious anxiety.
Autonomic nervous system responses can influence gut activity even when someone doesn't feel particularly worried or distressed.
The digestive system can become more sensitive.
Increased sensitivity to ordinary intestinal movement, pressure or stretching can contribute to discomfort and pain.
Symptoms can fluctuate.
Digestive symptoms may change in intensity, duration and presentation, sometimes varying considerably from one day to another.
-
Gastrointestinal distress can present in many different ways.
The uncomfortable fullness: Feeling excessively full or bloated, sometimes after eating relatively small amounts.
The unpredictable bowel: Experiencing changes between constipation, diarrhoea or periods of relatively normal bowel function.
The abdominal cramping: Feeling tightening, pressure or painful contractions in the stomach or intestines.
The persistent nausea: Experiencing an unsettled stomach or sensation of sickness, sometimes without vomiting.
The urgent need: Feeling a sudden or difficult-to-control need to use the toilet.
The sensitive stomach: Experiencing discomfort, pressure or pain during ordinary digestive activity.
The gut-brain connection: Noticing changes in digestive symptoms during periods of emotional stress, anticipation or heightened nervous system activity.
The invisible impact: Appearing well externally while managing pain, discomfort or concerns about unpredictable digestive symptoms.
For some people, digestive symptoms primarily involve pain or bloating. For others, bowel changes, nausea or difficulties with eating are more prominent.
The impact can extend beyond physical discomfort, influencing sleep, concentration, social activities, travel, work and everyday confidence.
-
Digestive symptoms can have many causes, including disorders of gut-brain interaction, inflammatory conditions, infections, medication effects and other health conditions.
New, persistent, worsening or unexplained digestive symptoms may warrant medical assessment.
Symptoms such as unexplained weight loss, persistent vomiting, blood in the stool, difficulty swallowing or significant changes in bowel habits can require further investigation.
Severe abdominal pain, vomiting blood, black tar-like stools or signs of significant dehydration may require urgent medical attention.
