The most common species to cause intestinal schistosomiasis are S. mansoni and S. japonicum, however, S. mekongi and S. intercalatum can also cause this disease.Symptoms may include:

Abdominal pain and discomfort
Loss of appetite
Mucous diarrhea with or without gross blood
Blood in feces that is not visibly present (fecal occult blood)
Abdominal distentionComplications may include:

Intestinal polyps
Intestinal ulcers
Iron deficient anemia
Fistula
Bowel strictures (narrowing of colon or rectum)
Protein-losing enteropathy
Partial or complete bowel obstruction
Appendicitis (rare)Approximately 10-50% of people living in endemic regions of S. mansoni and S. japonicum develop intestinal schistosomiasis. S. mansoni infection epidemiologically overlaps with high HIV prevalence in Sub-Saharan Africa, where gastrointestinal schistosomiasis has been linked to increased HIV transmission. Hepatosplenic Schistosomiasis
Eggs also migrate to the liver leading to fibrosis in 4 to 8% of people with chronic infection, mainly those with long-term heavy infection.Eggs can become lodged in the liver, leading to portal hypertension, splenomegaly, the buildup of fluid in the abdomen, and potentially life-threatening dilations or swollen areas in the esophagus or gastrointestinal tract that can tear and bleed profusely (esophageal varices). This condition can be separated into two distinct phases: inflammatory hepatic schistosomiasis (early inflammatory reaction) and chronic hepatic schistosomiasis. Most common species to cause this condition are S. mansoni, S. japonicum, and S. mekongi. Inflammatory hepatic schistosomiasis

This condition occurs mainly in children and adolescents due to early immune reaction to eggs trapped within the periportal and presinusoidal spaces of the liver creating numerous granulomas. Liver function is not affected, and the severity of liver and spleen enlargement is correlated to the intensity of the infection.
This is a good way to help exclude other similar lung diseases like sarcoidosis, infection and Idiopathic pulmonary fibrosis. Lung biopsy
Lung biopsies can be diagnostic in cases of chronic hypersensitivity pneumonitis, or may help to suggest the diagnosis and trigger or intensify the search for an allergen. The main feature of chronic hypersensitivity pneumonitis on lung biopsies is expansion of the interstitium by lymphocytes accompanied by an occasional multinucleated giant cell or loose granuloma.When fibrosis develops in chronic hypersensitivity pneumonitis, the differential diagnosis in lung biopsies includes the idiopathic interstitial pneumonias. This group of diseases includes usual interstitial pneumonia, non-specific interstitial pneumonia and cryptogenic organizing pneumonia, among others.The prognosis of some idiopathic interstitial pneumonias, e.g. idiopathic usual interstitial pneumonia (i.e. idiopathic pulmonary fibrosis), are very poor and the treatments of little help. This contrasts the prognosis (and treatment) for hypersensitivity pneumonitis, which is generally fairly good if the allergen is identified and exposures to it significantly reduced or eliminated. Thus, a lung biopsy, in some cases, may make a decisive difference. Serum Precipitins
Assays for serum IgGs can aid in identifying possible antigenic exposures and are used as markers of exposure  However, there use is limited in making a definitive diagnosis because serum antibody levels are often elevated in those people who are exposed to an antigen but do not have the disease. Up to 90% of people exposed to the antigen have precipitins but only 50% of similarly exposed people who are asymptomatic have the same precipitins.