Differential Diagnosis for Chronic Anal Fissures, Tenesmus, Post-Prandial Abdominal Distension and Pain, GERD, and Fatigue
Single Most Likely Diagnosis
- Irritable Bowel Syndrome (IBS): This diagnosis is likely due to the combination of chronic abdominal pain, post-prandial distension, and alteration in bowel habits (tenesmus), which are common symptoms of IBS. The presence of GERD and fatigue also supports this diagnosis, as they can be associated with IBS.
Other Likely Diagnoses
- Functional Dyspepsia: This condition can cause post-prandial abdominal pain and distension, and may coexist with IBS.
- Anal Fissure with Secondary Complications: Chronic anal fissures can cause tenesmus and pain, and may be associated with other anorectal conditions.
- Gastroesophageal Reflux Disease (GERD) with Complications: GERD can cause abdominal pain, distension, and fatigue, especially if complicated by conditions like esophagitis or stricture.
Do Not Miss Diagnoses
- Inflammatory Bowel Disease (IBD): Although less likely, IBD (including Crohn's disease and ulcerative colitis) can cause chronic abdominal pain, diarrhea, tenesmus, and fatigue. The presence of chronic anal fissures and post-prandial abdominal distension increases the suspicion for IBD.
- Colorectal Cancer: This is a critical diagnosis to consider, especially in older adults or those with a family history of colorectal cancer. Chronic abdominal pain, changes in bowel habits, and fatigue can be symptoms of colorectal cancer.
- Infectious Colitis: Infectious causes of colitis, such as Clostridioides difficile infection, can cause chronic diarrhea, abdominal pain, and fatigue.
Rare Diagnoses
- Celiac Disease: This autoimmune disorder can cause chronic abdominal pain, diarrhea, and fatigue, especially after eating gluten-containing foods.
- Small Intestine Bacterial Overgrowth (SIBO): SIBO can cause chronic abdominal pain, bloating, and diarrhea, and may be associated with conditions like IBS.
- Chronic Intestinal Pseudo-Obstruction: This rare condition can cause chronic abdominal pain, distension, and alterations in bowel habits, and may be associated with other systemic diseases.
Factors that would make IBD more likely include:
- Family history of IBD
- Presence of extraintestinal manifestations (e.g., arthritis, skin lesions)
- Significant weight loss or anemia
- Abnormal laboratory tests (e.g., elevated inflammatory markers, anemia)
- Endoscopic or imaging findings consistent with IBD (e.g., ulcers, strictures)