Crohn's disease is a long-term inflammatory disease of the intestines. According to the National Digestive Diseases Information Clearinghouse, no one knows for sure what causes Crohn's disease, although one theory is that it involves an autoimmune reaction. Although Crohn's can be seen in any part of the intestines, it is frequently seen in the ileum. When a flare-up occurs, a person experiences bouts of abdominal pain, diarrhea and vomiting.
Diarrhea
People experience frequent diarrhea during a Crohn's flare-up, especially after eating. The long-term inflammation affects the small intestine, making it unable to digest and absorb food properly. The absorption of water from the food is also affected, and this increases the excretion of water in the stools.
Abdominal Pain
People also commonly experience abdominal pain and cramping during a Crohn's flare-up. Swelling of the intestinal walls can develop due to the chronic inflammation, which can lead to scarring, and affects food passage through the bowels. Crohn's patients complain of abdominal discomfort and experience decreased appetite, which can cause weight loss.
Fever and bleeding
Increased body temperature is a sign of Crohn's flare-up, as the body reacts to the intestinal inflammation. Low-grade fevers occur in mild flare-ups, whereas high fevers can occur during acute and severe attacks.
Patients can experience blood in their stool during a flare-up. Food can irritate the inflamed tissues of the intestines as it passes through. This blood might not always be visible.
