Why does ulcerative colitis cause fatigue and bleeding at 29?

Question

Hello doctor,

I am 29 years old and was recently diagnosed with ulcerative colitis after months of diarrhea, abdominal pain, and urgency. I have started mesalamine treatment, but I still occasionally notice blood in my stools and continue to feel exhausted most of the time.

I would also like to know whether dietary changes can genuinely help reduce symptoms or prevent flares, or if medication is the main treatment approach.

Can ulcerative colitis cause anemia or problems with nutrient absorption?
Additionally, how do doctors decide when stronger treatments like biologic medications are needed in ulcerative colitis?

Please help.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query and understand your concern.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease affecting the colon. Ongoing inflammation and repeated blood loss through stools can commonly lead to iron deficiency anemia, which may explain your persistent fatigue.

In some cases, nutritional deficiencies such as low vitamin B12 or folate levels may also contribute.

Mesalamine is commonly used to control inflammation and maintain remission in mild to moderate UC. However, the presence of ongoing blood in stools may indicate that the inflammation is not yet fully controlled.

Dietary changes can help reduce irritation and improve symptoms during flares, although diet alone usually cannot control UC without medication. During active symptoms, some patients benefit from a low-residue or low-fiber diet temporarily to reduce bowel irritation.

It may also help to avoid personal trigger foods such as spicy foods, caffeine, alcohol, or highly processed foods. Keeping a food diary can sometimes help identify patterns.

Doctors usually consider stronger treatments such as biologic medications if symptoms remain active despite adequate mesalamine treatment, if repeated steroid courses are needed, or if the disease becomes moderate to severe with persistent bleeding, weight loss, frequent flares, or significant inflammation on testing.

Further evaluation may include:

Complete blood count (CBC) to check for anemia.
Iron studies, vitamin B12, and folate levels.
Inflammatory markers such as CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
Stool calprotectin to assess disease activity.

Continue regular follow-up with your gastroenterologist, as early adjustment of treatment can help reduce long-term complications and improve disease control.

I hope this helps.

Thank you.