Unlike popular belief that food is excreted immediately after eating, transit time for bowel is totally different. Food can take anywhere from 1 day to 3 days to get completely excreted. Till that time at least some particles of the food remains in the intestine. If you have bowel movement just after taking food, it is the food that was already present in the colon and not the one that you have taken. Some people have the habit of passing stool shortly after eating meals. Food particles travel from the mouth goes through esophagus and reaches the stomach. Here several enzymes and acids would act upon it converting it into semisolid chyme.
This would gradually pass into the small intestine where bile would play an important role in absorbing essential food nutrients. The leftover food particles would be sent to large intestine which gets mixed with fluid before getting ready for excretion. Average time the food remains in your abdomen is 12-48 hours. Bowel irritation can be the major cause for diarrhea immediately after eating. Sometimes, reflexive action of the nerves for passing stools get triggered prematurely creating sudden urge to use the toilet. There are people who get tempted to pass stool even while eating. The lower portion of the colon is filled with large volumes of feces which creates pressure. This force would trigger the nerve reflexes urging the person to pass the stool immediately.
Diarrhea can be defined as frequent loose movement of stool. Liquid bowel movements are common during diarrhea and the number of times you visit the toilet would be more. When a person has diarrhea the nerves that manage the bowel activity gets irritated. Due to constant pressure and irritation these nerves would affect other regions of the colon causing defecation reflexes or sudden bowel movement.
Symptoms Of Diarrhea :
Diarrhea is passing stool frequently and the texture of stool is loose and watery. It can cause other symptoms like pain in the abdomen before passing stool and thin watery stool more than 3 times a day.
Defecation Reflex :
Often these reflex reactions occur in the lower bowel but sometimes it gets triggered with force reaching till the stomach, causing abdominal pain before defecation. Network of nerves are seen running at different parts of the bowel. Out of which some carry signals to/from the brain and others control stretching of muscles responsible for defecating. It controls the stretching and relaxation of anal sphincter muscle that allows stool movement.
Two types of reflex can occur in the abdomen. The first one occurs by stretching of stomach, and is known as gastrocolic reflex causing pain and bowel movement shortly after eating. The second one occurs when the duodenum gets stretched and is known as duodenocolic reflex. Both the above types of reflexes would stimulate the colon and lower bowel creating an urge to pass stool.
Some of the important causes of diarrhea after eating is discussed here.
- Bowel Irritation :
The soft lining of the gut wall can get irritated and develop swelling. It becomes hyperactive pushing the bowels through the colon much quickly. This process can cause sudden urge to pass the stool immediately after eating. Such quick movement is called as peristalsis and it creates waves on the walls of the stomach. These waves would start with such a great force that it extends till the anus/rectum forcing the sphincter muscle to push the stool.
- Certain Foods :
Some kinds of food you eat can induce stomach irritation causing peristalsis forcing the bowel out of rectum shortly after eating.
- Food Poison :
Allergic food items and food poison can trigger defensive reaction in the abdomen. Eating contaminated foods would release toxins in the stomach causing diarrhea. You would be forced to expel feces within few minutes after eating such foods. Diarrhea can occur within half-an-hour after ingesting food and it may continue up to 8 hours expelling every particle of allergic food from the colon.
- Gastroenteritis :
Gastroenteritis also known as “stomach flu” is a viral infection causing irritation of the stomach. Eating polluted food or drinking contaminated water can cause stomach flu. Children are more likely to develop gastroenteritis symptoms than adults. It may cause symptoms like sudden abdominal cramps, nausea, vomiting and mild fever. Contact with infected person is enough for developing stomach flu. Infants, children and older adults are at risk of developing gastroenteritis due to weakened immunity. Certain kind of virus like Norovirus and Rotavirus can cause gastroenteritis leading to diarrhea after eating.
- Magnesium :
Magnesium is normally safe for consumption if it is taken within the limit (less than 350 mg). Eating magnesium rich foods like nuts, fish, leafy greens, whole grains, yogurt and bananas in large quantities can cause diarrhea after eating. In severe cases it can cause complications like lowered blood pressure, shortness of breath, irregular heartbeat and vomiting.
- Infections :
Both viral and bacterial infection can cause diarrhea after eating. Undercooked meat contains bacteria which can force you to expel stool shortly after eating.
- Other Causes :
Certain powerful antibiotics taken along with food can destroy good bacteria in the intestine causing diarrhea. People who suffer from lactose intolerance and those who use artificial sweeteners can trigger diarrhea immediately after eating food.
Mal-absorption of fructose can trigger diarrhea and bloated feeing. Certain medical conditions like irritable bowel syndrome can suddenly aggravate bowel activity without no apparent cause causing sudden diarrhea. Likewise inflammatory bowel disease can cause swelling of stomach wall forcing the bowel through the rectum without proper absorption. Stress and anxiety can also cause diarrhea abruptly after eating.
You can control diarrhea easily if caused by allergic foods by avoiding such items completely. Identify the list of foods that induce diarrhea and avoid it. It is essential to keep your body hydrated when you have loose stool since you will be losing plenty of fluids. Eating Probiotics like yogurt and other OTC supplements can control diarrhea. You can follow the instructions given by the doctor if you have IBS/IBD to prevent diarrhea after eating.