Common symptoms for inflammatory bowel diseases differ by the infection level, but may include severe abdominal pain, diarrhoea, fatigue and unexpected weight loss. Crohn's disease can lead to infection of any part of the digestive tract, including ileum to anus. Internal manifestations include diarrhoea, abdomen pain, fever, chronic anaemia, etc. External manifestations include impact on skin, joints, eyes and liver. Significantly reduced "microbat diversity" inside the gastrointestinal tract can also be observed. Ulcerative colitis mainly affects the function of the large bowel, and its incidence rate is three times larger than the Crohn's disease. In terms of clinical features, over 90% of patients exhibited constant diarrhoea, 'rectal bleeding, softer and mucus in the stool, tenesmus and abdomen pain'. At the same time, patient also reported to be having "arthralgia, episcleritis and erythema nodosum". The symptoms can continue for around 6 weeks or even more than that.
