The brain-gut connection

In the coming year, a team of researchers from Canada and the U.S. will begin a study to determine the best way to treat the worst gut problems, including severe diarrhea, gas, bloating, nausea and “chronic constipation where you have excruciating cramps [that feel] like labour pain,” says Brenda Toner, a psychologist and co-head of social equity and health research at the Centre for Mental Health and Addiction, who is leading the investigation. But they won’t be looking at antacids, laxatives or enemas. The most effective remedies may be ones normally prescribed for mental illness: antidepressants or talk therapy, or both. “What I’ve been trying to do is put the mind and the body back together,” says Toner, who heads the women’s mental health department at the University of Toronto.

This surprising study is the latest research acknowledging the connection between anxiety or depression and gastrointestinal problems. “Most of us, when we’re under stress, respond with a GI symptom,” says Toner, up to 70 per cent of people, in fact. Think about how sick to your stomach you felt before that big meeting or when you were worried about someone you love. Gut discomfort is one of the biggest reasons people miss school or work, second only to the common cold. And for people whose pain is persistent, which is typical because many GI disorders are chronic, the psychological impact can be devastating. “The brain-gut interaction is a prominent one,” says Nicholas Diamant, a gastroenterologist and professor of medicine at the University of Toronto, who is working with Toner on the study. “There are a lot of things about gut symptoms that impact patients in a mental way,” he explains, which “will not only affect their mood but also their behaviours—whether they go to work or out to socialize.”

The physical pain is real and dogged. “On bad days it feels, literally, like somebody has taken a knife and stabbed it in my lower left side and is dragging it across my stomach,” says Jeffrey Roberts, 47, who has suffered from irritable bowel syndrome since he was a teenager. The symptoms fluctuate between diarrhea, constipation, nausea and cramps. Roberts, who lives in Toronto, is also lactose intolerant and was diagnosed with Crohn’s disease on his 40th birthday. The gut discomfort has forced him to reschedule a family trip to Disney World and cancel an Italian romantic getaway with his wife.

One of the most famous victim of eviscerating GI pain was Kurt Cobain, who hauntingly foreshadowed his own death when describing how gut symptoms sent him into a downward spiral: “It had been building up for so many years that I was suicidal. You know, waking up starving, forcing myself to eat, barfing it back up . . . just crying at times, ‘Urgh, I’m in pain all the time.’ ”

On top of the physical distress, Roberts says he and others like him suffer mental and emotional symptoms. (Cobain’s proof.) Anxiety and depression begin to creep in. “You worry that people see you as a hypochondriac,” he says, “as if it’s all in my head.” Some sufferers feel hopeless, which is a common reaction to chronic pain. Even the practical aspects of living with a major gut problem—always needing to know there’s a bathroom nearby, for example—can wear people down. ‘‘I don’t know anything that is more distressing for a patient,” says Diamant, a senior scientist at Toronto Western Research Institute, “than to fill their pants full of poop at the grocery store.”

The body, of course, reacts to stress in all kinds of ways. The cardiac system may respond with a hastened heartbeat; the vascular and nervous systems may cause a migraine headache. “But the gut seems to be the one [system] that’s more sensitive,” says William Paterson, a neurogastroenterologist and research chair at Queen’s University in Kingston, Ont. The gut includes everything from the salivary glands, the pharynx and esophagus to the stomach, intestines and anus, plus organs like the liver and pancreas. It’s huge and complex. “There are more nerves in the wall of the gut than there are in the spinal cord,” says Paterson, past president of the Canadian Association of Gastroenterology. It’s so responsive that scientists often refer to the gut as the “little” or “second” brain.